
Copyright N°_^2/^2 



COPYRIGHT DEFOSIT. 



Ube IRural Science Series 

Edited by L. H. BAILEY 



FERTILIZERS 



Wfyz Eural Science Series 

Edited by L. H. Bailey 

The Soil. King. 

The Spraying of Plants. Lodeman. 

Milk and its Products. Wing. Enlarged and Revised. 

The Fertility op the Land. Roberts. 

The Principles of Fruit-growing. Bailey. 20th 

Edition, Revised. 
Bush-fruits. Card. 
Fertilizers. Voorhees. Revised. 
The Principles of Agriculture. Bailey. Revised. 
Irrigation and Drainage. King. 
The Farmstead. Roberts. 
Rural Wealth and Welfare. Fairchild. 
The Principles of Vegetable-gardening. Bailey. 
Farm Poultry. Watson. Enlarged and Revised. 
The Feeding of Animals. Jordan. 
The Farmer's Business Handbook. Roberts. 
The Diseases of Animals. Mayo. 
The Horse. Roberts. 
How to Choose a Farm. Hunt. 
Forage Crops. Voorhees. 

Bacteria in Relation to Country Life. Lipman. 
The Nursery-book. Bailey. 
Plant-breeding. Bailey and Gilbert. Revised. 
The Forcing-book. Bailey. 
The Pruning-book. Bailey. 

Fruit-growing in Arid Regions. Paddock and Whipple. 
Rural Hygiene. Ogden. 
Dry-farming. Widtsoe. 
Law for the American Farmer. Green. 
Farm Boys and Girls. McKeever. 
The Training and Breaking of Horses. Harper. 
Sheep-farming in North America. Craig. 
Cooperation in Agriculture. Powell. 
The Farm Woodlot. Cheyney and Wentling. 
Household Insects. Herrick. 
Citrus Fruits. Coit. 

Principles of Rural Credits. Morman. 
Beekeeping. Phillips. 
Subtropical Vegetable-Gardening. Rolfs. 



FERTILIZERS 



THE SOURCE, CHARACTER AND COMPOSITION 
OF NATURAL, HOME-MADE AND MANUFAC- 
TURED FERTILIZERS, AND SUGGESTIONS 
AS TO THEIR USE FOR DIFFERENT 
CROPS AND CONDITIONS 



BY THE LATE 

EDWARD B. VOORHEES, A.M., D.Sc. 

DIRECTOR OF THE NEW JERSEY AGRICULTURAL EXPERIMENT 

STATIONS, AND PROFESSOR OF AGRICULTURE 

IN RUTGERS COLLEGE 



REVISED EDITION BY 

JOHN H. VOORHEES, B.Sc. 

ASSISTANT AGRONOMIST NEW JERSEY EXPERIMENT STATION 

INSTRUCTOR IN SOIL FERTILITY, NEW JERSEY 

STATE COLLEGE OF AGRICULTURE 

\ 



THE MACMILLAN COMPANY 
1916 

All rights reserved 



S633 
6 



.V°l 



° 



Copyright, 1898 
By EDWARD B. VOOEHEES 



Set up and electrotyped. Published November, 1898. Reprinted 
with corrections January, 1900; January and February, 1902; 
February, 1903; August, 1904; August, 1905; January, 1907; March 
and October, 1908; February, April and October, 1910; June, 1911; 
January and June, 1912; August, 1913; August, 1914. 



Revised Edition. Copyright, 1916 
By JOHN H. VOORHEES 



Set up and electrotyped. Published May, 1916. 



Norfonorj ^ressa 

J. S. Cushing Co. — Berwick & Smith Co. 

Norwood, Mass., U.S.A. 



JUN -i 1916 



•CI.A433222 



CONTENTS 

CHAPTER I 

PAGES 

The Natural Fertility of the Soil and Sources op 

Loss oe the Elements op Fertility . . . 1-19 

Soil Fertility — Chemical elements needed in plant 
growth — Fertility as influenced by water, climate and 
season — The influence of physical character of soil — 
Location of soil qualifies the term "fertility" — Prac- 
tical fertility is usable potential fertility . . . 2-6 

What Becomes of Our Fertility f 7 

Sources of Natural Loss of Nitrogen — Importance 
of careful culture — Loss of nitrogen by drainage — 
Escape of nitrogen into the atmosphere .... 8-11 

The Natural Loss of the Mineral Elements — Losses 
due to mechanical means 11-12 

Artificial Losses of Fertility — A comparison of the 
prices received for the fertility elements in different 
crops — Fertility content of cereals and vegetables — 
Irrational farm practice — Losses in manures . . 13-19 

CHAPTER II 



The Function op Manures and Fertilizers, and the 
Need of Artificial Fertilizers 

The Essential Elements of Fertilizers 
Natural Manures and Artificial Fertilizers 
Direct and Indirect Effect of Manures 
Unavailable and Available Plant-food 
Danger of Loss from the Use of Soluble Plant-food 
The Usefulness of a Fertilizer Constituent does not 
Depend upon Its Original Source . 

Use of Fertilizers 

v 



20-35 

20 

21 

22-23 

23-25 

25 

26 
27-28 



vi Contents 

PAGES 

The Need of Artificial Fertilizers — The cost of pro- 
duction to a unit of income is increased — A greater de- 
mand for special crops — Farm manures are inadequate 

— The growing importance of fruit-growing . . . 28-33 
Will it Pay to Use Fertilizers ? 33-35 

CHAPTER III 
Nitrogenous Fertilizers ....... 36-60 

What is Meant by Form of Nitrogen ? 36-37 

Dried Blood 37-39 

Dried Meat or Meal, Azotin, Ammonite, or Animal 

Matter 39 

Dried and Ground Fish, or Fish Guano . . . 39-40 

Tankage 40-41 

Garbage Tankage 42 

Low-grade Nitrogenous Products — Horn meal or 

ground horn — Leather meal — Wool and hair waste . 42-43 
Vegetable Nitrogenous Products — Cottonseed meal 

— Linseed meal — Castor pomace — Vegetable pomaces 43-44 
Natural Guanos — Mechanical Condition should be 

considered 44-47 

Ammonia Compounds — Sulfate of ammonia — Cal- 
cium cyanamid . 47-50 

Nitrate Nitrogen — Nitrate of soda — Calcium nitrate 

— Potassium nitrate — Ammonium nitrate . . . 50-53 
The Belative Availability of the Different Forms of 

Nitrogen — Comparative availability of different nitrog- 
enous substances — Conditions which modify avail- 
ability 53-60 

CHAPTER IV 

Phosphates — Their Sources, Composition, and Rela- 
tive Value ......... 61-80 

Phosphate of Lime, or Bone Phosphate — Animal 
Bone — Raw bone — Fine bone — Boiled and steamed 
bone — Commercial grades of bone — Bone tankage — 
Other organic products — Bone-black, or animal char- 
coal — Bone-ash 62-68 



Contents 



vn 



Mineral Phosphates — South Carolina rock phosphates 

— Florida phosphates — Canadian apatite — Tennessee 
phosphate — Recent discoveries in western states — Basic 
slag — Manufactured phosphates — Artificial basic- 
slag meal — Wiborgh phosphate — Wolter phosphate — 
Palmaer phosphate — Phosphatic guanos 

Phosphates as Sources of Phosphoric Acid to Plants 

— The influence of source of phosphate upon availability 

— Influence of fineness of division — The character of 
soil as a factor influencing availability — Influence of 
the kind of crop — General considerations 



68-75 



75-80 



CHAPTER V 

Superphosphates — Potash 81-101 

Insoluble Phosphoric Acid 81-82 

Soluble Phosphoric Acid 82 

Reverted Phosphoric Acid 82-83 

How Superphosphates are Made — The difference in 
the superphosphates made from the different materials 
— Soluble phosphoric acid chemically identical, from 

whatever source derived 83-85 

Phosphates and Superphosphates are not Identical . 85-89 
Double Superphosphates . . . . . . 89-90 

Chemical Composition of Superphosphates — Well- 
made superphosphates contain no free acid — Phosphoric 
acid remains in the soil until taken out by plants . . 90-93 

Potash Salts — The importance of potash as a con- 
stituent of fertilizers — Forms of potash — Kainit — 
Hardsalt — Carnallit — Muriate of potash — High-grade 
sulfate of potash — Double manure salt — Potash manure 
salt — Double carbonate of potash and magnesia — Po- 
tassium carbonate — Potassium nitrate — Feldspar and 
other minerals as a source of potash — Seaweeds as a 
source of potash — Fixation of potash .... 93-101 



CHAPTER VI 
Miscellaneous Fertilizing Materials .... 

Tobacco Stems and Stalks — Tobacco salts — Crude 
fish scrap — Wool and hair waste — Sewage — Muck and 



102-118 



viii Contents 



peat — King crab, mussels and lobster shells — Seaweed 

— Wood-ashes and Tanbark-ashes — Coal-ashes — Cot- 
ton-hull-ashes — Corn-cob-ashes — Cocoa shells — Green 
sand marl — Agricultural salt — Powder waste — 
Gas lime — Gypsum or calcium sulfate — Phosphorus 
powder — Calcium carbide waste — Oxy-acetylene 
residue — Purchase and use of miscellaneous materials . 118 

CHAPTEE VII 

Farmyard and Green-manures . . . . . 119-134 

Farmyard Manures — Variations in manures — Ma- 
nure produced by different animals — Composition of 
stable manure — Solid and liquid portions — Sources of 
loss in manures — Care of manures — Manure preserva- 
tives — The improvement of manures — Application of 
yard manure — Poultry and pigeon manure — Composts 119-128 

Green-manures — "Nitrogen gatherers" and "nitro- 
gen consumers ' ' — The most useful crops — Green- 
manure crops that consume the nitrogen in the soil — 
Mixtures are advisable — Precautions in the use of 
green-manures 128-134 

CHAPTER VIII 

Lime and Calcium Compounds ...... 135-152 

Occurrence of Lime 136 

Forms on the Market — Caustic lime — Ground lime- 
stone — Calcium-magnesium lime — Ground burned 
lime — Hydrated lime — Air-slaked lime — Oyster shell 

lime — Shell marl 136-140 

Action of Lime on Soils — Mechanical effects of lime 

— Chemical effects of lime — Lime supplies a necessary 
base — Lime assists the decomposition of organic matter 

— Lime makes soil potash available — Lime makes soil 
phosphates available — Less plant-food required — Inju- 
rious chemical effects — Effects of gypsum . . . 140-145 

Biological Effects of Lime — Biological effects may 
be harmful 145-146 



Contents 



IX 



The Use of Lime — Do soils need lime ? — The appli- 
cation of lime — When and how to apply lime — The 
form of lime to use — Distribution of lime — Analysis 
and guarantee 



146-152 



CHAPTER IX 

Purchase of Fertilizers 153-174 

Standard High-grade Materials 154-155 

Fertilizing Materials Variable in Composition . . 155-156 
High-grade and Low-grade Fertilizers — The "unit" 
basis of purchase — The " ton " basis of purchase — The 
necessity of a guarantee — Laws alone do not fully pro- 
tect — Method of statement of guarantee sometimes mis- 
leading — Discussion of guarantees — Raw materials — 
Mixed fertilizers — The advantages and disadvantages 
of purchasing raw materials and mixed fertilizers . . 156-167 
Home Mixtures — Formulas — The cost of handling 

"make-weight " 167-173 

General Advice 173-174 



CHAPTER X 

Chemical Analyses of Fertilizers . 
The Interpretation of an Analysis 
The Agricultural Value of a Fertilizer 
The Commercial Value of a Fertilizer 
Calculation of Commercial Values 
The Uniformity of Manufactured Brands 



175-190 
175-178 
178-179 
179-187 
187-188 
188-190 



CHAPTER XI 

Methods of Use of Fertilizers 

Conditions which Modify the Usefulness of Fertilizers 



191-211 



— Derivation of soil a guide as to its possible deficiencies 

— Physical imperfections of sandy soils — Physical im- 
perfections of clay soils — The influence of previous 
treatment and cropping — The influence of character of 
crop — The kind of farming, whether " extensive " or 

" intensive " 191-199 



Contents 



Plants Vary in their Power of Acquiring Food — 
Characteristics of the cereal group — Characteristics of 
grasses and clovers — Root crops — Market-garden crops 

— Fruit crops 199-204 

Systems of Fertilizing Suggested — A system based 

upon the specific influence of a single element — A sys- 
tem based upon the necessity of an abundant supply of 
the minerals — A system based on the needs of the plants 
for the different elements as shown by chemical analysis 

— A system in which the fertilizer is applied to the 
"money crop" in the rotation — An irrational system 204-210 

Summary 210-211 

CHAPTER Xn 

Fertilizers for Cereals and Grasses .... 212-236 
Experiments to Determine the Lacking Element — A 
scheme for plot experiments — Results that may be at- 
tained 214-219 

The Importance of System in the Use of Fertilizers — 
Indian corn exhaustive of the fertility elements — Oats 

— Barley — Wheat — Rye — Clover — Timothy — A 
gain of fertility by the rotation system — The necessity 
of adding more plant-food than is required by a definite 
increase in crop — The system should be modified if no 

farm manures are used 219-231 

Fertilizers for a Single Crop Grown Continuously . 231-233 

Fertilizers for Meadows 234-235 

Will this System of Fertilizing Pay?. . . . 235-236 

CHAPTER Xni 

Field Truck Crops 237-259 

Fertilizers for Potatoes, Early Crop — The time and 
method of application — The amount to be applied — 

Form of the constituents 238-243 

Late Potatoes 243-244 

Sweet Potatoes — Fertilizer constituents contained in 
an average crop — The application of the fertilizers . 244-248 



Contents 



XI 



Tomatoes — Field experiments with fertilizers for 
tomatoes — Fertilizers for the early crop for different 
conditions of soil — The use of fertilizers with yard ma- 
nures — Fertilizers for late tomatoes 

Peppers and Eggplant 

Peas and Beans .... 

Field Beans .... 

General Considerations 



248-257 
257 

257-258 
258 
269 



CHAPTER XIV 
Green Forage Crops 260-282 

Cereals and Grasses — Maize (corn) forage — Silage 
corn — Wheat and rye forage — Spring rye — Oats — 
Oats and peas — Barley and peas — Millet — Orchard 
grass — Italian rye grass — Bermuda grass . . . 260-269 

Clovers and Other Legumes — Japan clover — Cow- 
pea and soybean — Spring vetch — Hairy or winter 
vetch — Alfalfa or lucerne — Sweet clover — Need of 
lime for legumes — Fertilization of soiling crops . . 269-277 

The Cabbage Tribe — Rape — Cabbage — Kohlrabi . 277-279 

Boot Crops — Fertilizers for fodder-beets, sugar-beets 
and carrots — Turnips and swedes .... 279-282 

Tuber Crops 282 



CHAPTER XV 

Market-garden Crops 283-307 

The Yield and Quality Dependent upon Continuous 
and Bapid Growth — A basic fertilizer for market-garden 

crops — The different kinds of vegetables . . . 283-289 

Boot Crops — Beets and turnips — Carrots . . 289-291 

Bulb Crops 291-293 

Cole Crops 293-294 

Pot Herbs 294-295 

Salad Crops — Celery — Lettuce .... 296-296 

Pulse Crops 296-297 

Solanaceous Crops — Eggplant — Peppers — Toma- 
toes 297-299 

Vine Crops 299-300 



xii Contents 



Miscellaneous Crops — Asparagus — Rhubarb — 

Sweet corn— Okra 300-306 

Condimental or Sweet Herbs 306-307 

CHAPTER XVI 

Orchard Fruits and Berries 308-331 

Fruit Crops differ from General Farm Crops . . 308-309 
The Specific Functions of the Essential Fertilizing 

Constituents . 310 

The Character of Soil an Important Consideration . 311-312 

The General Character of the Fertilizing . . . 312-313 

The Application of Fertilizers for Fruits . . . 314 
The Fertilizing of Apples and Fears — The amounts 

to be applied 314-318 

Peaches — The need of fertilizers — Methods of fer- 
tilizing 318-325 

Plums, Cherries, and Apricots 325 

Citrous Fruits 325-326 

Small Fruits — Strawberries — Raspberries and 

blackberries — Currants and gooseberries — Cranberries 326-330 

Grapes 330 

CHAPTER XVII 
Fertilizers for Various Special Crops .... 332-357 
Cotton — Fertilizers for cotton — Formulas for cotton 
fertilizers — Method of application .... 332-338 

Tobacco — The influence of fertilizers on the quality 
of the crop — The conclusions from Connecticut experi- 
ments — Form of the constituents — Amounts to apply 338-343 
Sugar-beets — The demands of the crop for plant-food 

— The influence of previous deep cultivation of soil . 343-346 
Sugar-cane — The needs of the plant as indicated by 

the Louisiana experiments — The application of fertilizers 347-350 

Hops 350-351 

Flax ' 351 

Miscellaneous Crops — Sorghum — Buckwheat — Pea- 
nut — Roses, and other flowering plants — Lawn grasses 

— Forcing house crops 351-357 



LIST OF ILLUSTRATIONS 



Plate I. Fig. 1. Coke-oven Plant, Gary, Indiana, 
where ammonium sulfate is an important 
by-product opposite 32 

Plate II. Fig. 2. Cylinder Experiments at the New 

Jersey Agricultural Experiment Station . " 54 

Plate III. Phosphate Mining " 70 

Fig. 3. Phosphate Pit, Dunnellon, Florida. 
Fig. 4. Mining Phosphate Eock by Means of 
Floating Dredge. 

Plate IV. Mining and Composting " 98 

Fig. 5. Mining Phosphate Eock by Hydraulic 
Pressure. 

Fig. 6. The Manure Spreader is a Labor-saving Device 

which secures an Even Distribution .... 125 

Plate IV. Mining and Composting .... opposite 98 
Fig. 7. Unloading and Composting New York 
Stable Manure in South Jersey. 

Plate V. Fertilizers and Wheat .... " 120 

Figs. 8 and 9. Continuous Wheat Cropping with 
and without Green-manures, New Jersey 
Experiment Station. 

Plate VI. Wheat and Potatoes .... " 140 

Fig. 10. Wheat Grown as a Winter Cover- 
crop Preceding Potatoes, Freehold, New 
Jersey. 

Plate VII. Fertilizers and Eye . . . . " 158 

Figs. 11 and 12. Eye with One-half Ton of 
Lime and without Lime, 
xiii 



XIV 



List of Illustrations 



Plate VI. Wheat and Potatoes .... 
Fig. 13. Making an Application of One and 
One-half Tons of Quicklime to the Acre for 
Alfalfa after Potatoes. 

Fig. 14. Grain Drill with Fertilizer Sower 

Plate VIII. Wheat and Timothy .... 

Fig. 15. Thirty-five Bushels of Wheat to the 
Acre, Mechanicsburg, Pennsylvania. 

Fig. 16. Early Spring Top-Dressing with Com- 
mercial Fertilizer High in Available Nitrogen 
Greatly Increases the Yield of Timothy. 

Plate IX. Lima Beans and Potatoes 

Fig. 17. Ninety-acre Field of Lima Beans for 
Canning, Freehold, New Jersey. 

Fig. 18. The Potato-planter with Fertilizer Attach- 
ment, which distributes Fertilizer evenly in 
the Kow 



PAGE 

opposite 140 



. 213 
opposite 178 



Plate IX. Lima Beans and Potatoes 

Fig. 19. One Ton of High-grade Fertilizer Used 
upon Early Potatoes is the Common Practice 
among Growers in New Jersey. 

Plate X. Fertilizers and Tomatoes .... 
Fig. 20. Early Tomatoes Grown in Light, 

Sandy Soil, Thorofare, New Jersey. 
Fig. 21. Growth of Clover along Tomato Rows 

Heavily Fertilized the Preceding Year, 

Moorestown, New Jersey. 

Plate XL Peppers and Red Clover .... 
Fig. 22. Peppers Grown under Field Conditions, 
Thorofare, New Jersey. 

Plate XII. Fig. 23. Oats and Canada Field Peas 
respond to Good Fertilization 

Plate XL Peppers and Red Clover .... 
Fig. 24. Excellent Second Growth of Red 
Clover on Heavily Fertilized Potato Land, 
Freehold, New Jersey. 



202 



240 



opposite 202 



220 



234 



260 
234 



List of Illustrations xv 

PAGE 

Plate XIII. Fig. 25. Dwarf Essex Rape mixed with 
Soybeans and Sweet Clover, and Heavily 
Fertilized, makes a Luxuriant Forage . opposite 278 

Fig. 26. Garden Fertilizer Sower 284 

Fig. 27. Garden Fertilizer Sower with Hoe to work 

Fertilizer into Surface Soil 288 

Plate XIV. Cabbage and Watermelons . . . opposite 294 
Fig. 28. Cabbage Heavily Fertilized, Freehold, 

New Jersey. 
Fig. 29. Watermelons, Peppers, and Corn 
Fertilized with Basic Fertilizer, Clarksboro, 
New Jersey. 

Plate XV. Fertilizers for Peaches .... " 318 

Figs. 30 and 31. Views of the Vineland Experi- 
mental Peach Orchard, New Jersey Experi- 
ment Station, showing (Fig. 30) Effect of 
Nitrogen in Addition to Minerals; Fig. 31, 
below, Minerals Only, No Nitrogen. 

Plate XVI. Fig. 32. Tobacco, Lancaster area, 

Pennsylvania " 338 



FERTILIZERS 



CHAPTER I 

NATURAL FERTILITY OF THE SOIL, AND 
SOURCES OF LOSS OF THE ELEMENTS OF 
FERTILITY 

There is no one question of greater importance to 
the farming industry than that of soil fertility. In 
order that the industry may be successful, it is not enough 
to produce crops; it is necessary that their production 
shall result in a genuine profit. That is, it is not enough 
to produce crops which bring more than they cost in the 
way of labor and manures, without taking into consid- 
eration the effect of their growth upon the future pro- 
ductive capacity of the soil. The relation of the outgo 
and income of the fertility elements is an important 
factor in determining profits, and must be considered. 
The farmer who secures crops that bring more than they 
cost, and who, at the same time, maintains or even 
increases the productive capacity of his soil, is, other 
things being equal, the broadly successful farmer. Many 
farmers are able to accomplish this object because of the 
knowledge they have acquired through long years of 
experience, rather than because they possessed in the 
beginning of their work a definite knowledge of the fun- 
damental principles involved in crop production, and 



2 Fertilizers 

upon the observance of which their success depended. 
One of the first needs, therefore, in the use of commercial 
fertilizers is a more or less definite knowledge of what 
constitutes fertility, and of the principles which under- 
lie crop production. 

SOIL FERTILITY 

The full meaning of the term "soil fertility" is not 
easily expressed, since many conditions are involved, 
all of which exert more or less influence. The po- 
tential fertility, which is measured by the total content 
of the food elements contained in a soil, is made prac- 
ticable, or usable, in proportion as the conditions are 
favorable. The more important of these influencing 
conditions are here briefly discussed. In the first place, 
it is of the utmost importance that a soil should contain 
those elements found in the plant; hence, it is almost 
self-evident that a fertile soil must contain a maximum 
quantity of those particular elements or constituents 
which are removed from the land in maximum amounts 
by the crops grown. The removal of crops rapidly ex- 
hausts the soil of these elements, and finally reduces the 
quantity contained in the soil to so low a point as to make 
profitable cropping impossible. 

Chemical elements needed in plant growth. 

Careful studies and experiments have shown that 
plants actually take from the soil at least ten chemical 
elements which are required for their normal growth and 
development: viz., nitrogen, potassium, phosphorus, 
magnesium, sulfur, sodium, iron, chlorin, silicon and 
calcium. Besides these elements, others are often found, 
including manganese. It is not to be inferred that all 



Natural Fertility of the Soil 3 

of these elements are required by all plants. There 
are many plants which grow to maturity without 
sodium, silicon and chlorin, but all of the others must 
be present for normal growth. Carbon, hydrogen and 
oxygen are also found in plants, but these elements are 
secured from air and moisture. 

The number of soil constituents liable to rapid exhaus- 
tion is limited in many cases to three, and at most to four, 
which are nitrogen, phosphoric acid (phosphorus), 
potash (potassium), and lime (calcium), the latter only 
in exceptional cases. These are liable to be exhausted 
because they exist in larger amounts than the others in 
the plants that are grown, and in smaller amounts than 
the others in even the most fertile soils. It has also been 
proved that it is the one element of these which exists in 
the smallest amount which measures the crop-producing 
power, or fertility, in this respect, as one element cannot 
substitute or exert the full functions of another. That is, 
there may be a relative abundance in the soil of potash 
and of phosphoric acid, but practically no nitrogen, in 
which case good crops of cereals, for instance, could not 
be grown, because no other element can substitute the 
nitrogen required by the plant, and it can be obtained by 
it from no other source than the soil ; and the soil, for all 
practical purposes, is quite as unproductive, lacking in 
productive fertility, as it would be if it contained much 
smaller amounts of the mineral elements mentioned, and 
thus be poorer in potential fertility. 

Fertility as influenced by water, climate and season. 

In the second place, there are soils that are so rich 
in all of these elements that if productiveness depended 
upon them alone, maximum crops might be grown for 



4 Fertilizers 

centuries without exhausting them, while actually they 
are now incapable of producing a single profitable crop 
of cereals, grasses, fruits or other products of the farm, 
because certain other conditions which are essential, in 
order to bring them into activity, are absent. For ex- 
ample, it may be that water, which is absolutely essen- 
tial both for the solution of these food elements in the 
soil, as well as for their distribution in the plant after they 
have been acquired, cannot be obtained, or that the tem- 
perature of the soil and of the surrounding air is either 
too low or too high, thus preventing or interrupting the 
progress of those changes which must go on, both in the 
soil and in the plant, in order that normal growth and 
development may be accomplished. With a full supply of 
the fertility elements in the soil, the climatic and seasonal 
conditions exert an important influence upon its produc- 
tive power. 

It is evident, therefore, that the chemical elements of 
fertility in themselves are not sufficient to constitute what 
we understand by the term. Fertility is not measured 
by them alone ; associated with them there must be other 
conditions. That is, while crops cannot be grown with- 
out these elements, it is the conditions which surround 
them that, in a large degree, determine the power of the 
crop to secure them. 

The influence of physical character of soil. 

In the third place, the physical character of a soil is 
also a factor in determining actual fertility. This has 
reference, first, to the original character of the rocks from 
which the soil particles were derived, whether hard and 
dense in their mineral character, thus resisting the pene- 
tration and the solvent effect of air and water and other 



Natural Fertility of the Soil 5 

agencies, or whether soft and friable, and freely permit- 
ting their entrance and action; and secondly, whether, 
in the formation of the soil, the particles were so fine 
and so free from vegetable matter as to settle in hard 
and compact masses, impervious to water, air and 
warmth; or whether they were coarse, and not ca- 
pable of close compaction, thus giving rise to an open 
and friable soil, freely admitting the active natural 
agencies, such as we find to be the case in sandy soils. 
In addition to these properties of soils, which have a 
distinct place in determining fertility, there are many 
other minor ones which together constitute what is 
understood as "condition." 

Location of soil qualifies the term "fertility." 

Furthermore, fertility, even in this true sense, may 
be useless because of the location of the soil which 
possesses it. For example, there are many places on 
this continent where sugar-producing plants will grow 
and develop perfectly, since the soils are very rich in 
the fertility elements, and since the surrounding con- 
ditions are most favorable for their culture, yet, be- 
cause of their location, it is unprofitable to grow them 
for the manufacture of sugar. In the first place, the 
soils are so situated as to make it impossible, or at 
least impracticable, to provide the means necessary for 
converting the sugar-producing crop into actual sugar, 
and, in the second place, even if it were possible to 
do so, the great distance from shipping stations to 
markets so increases the cost of transportation as to 
make it unprofitable to compete in the market with the 
crops grown upon lands possessing true fertility in a lower 
degree. 



6 Fertilizers 

Practical fertility is usable potential fertility. 

Practical fertility, therefore, is dependent upon many 
conditions, and fortunately our own country possesses it 
in a marked degree ; that is, the utility of the potential 
fertility, as represented by the total mineral content of 
our soil, is such as to make us one of the greatest agricul- 
tural nations in the world, both in the quantity and variety 
of products grown. Our soils possess the essential ele- 
ments in lavish amounts, and our climatic and seasonal 
conditions are such as to permit of their ready conversion 
into a wide series of valuable products, and our location 
and facilities for handling and distributing our staple 
crops are such as to enable us to compete in any market 
of similar commodities. 

Notwithstanding the truth of this general statement, 
it is also true that in certain sections of our country 
profitable crops cannot be grown without the addi- 
tion of commercial fertilizers, because the soils are 
either naturally poor, or they have become partially 
exhausted of their plant-food elements. That is, the 
amounts that become available to the plant through 
the growing season are not sufficient to enable the plant 
to reach a maximum development, though other condi- 
tions are perfect. 

Our future progress depends, therefore, upon how well 
we understand and apply the principles which are in- 
volved, both in the conservation and use of the fertility 
stored up in our soils, and in the use of purchased fertility ; 
and in this connection it is important to consider the 
sources of loss of the essential fertility elements, or those 
which in the beginning measured our capabilities in crop 
production. 



Natural Fertility of the Soil 7 

WHAT BECOMES OF OUR FERTILITY? 

Since fertility is dependent upon so many conditions, 
or, in other words, since the essential elements of fertility 
are dependent upon their utility, and since, in this sense, 
fertility is largely determined by natural conditions, it is 
pertinent to inquire, first, whether under our present 
systems of management, or mismanagement, of the land, 
it is suffering any natural loss of fertility. As already 
pointed out, the most important function of fertility is 
to furnish nitrogen, phosphoric acid and potash, and 
since the content of these in our soil, together with the 
knowledge we have as to their use, measures, in a sense, 
our prosperity as an agricultural people, the possibilities 
of losing them from the soil is a matter of national con- 
cern, and is of vital interest to individual farmers, who, 
in the aggregate, make up that part of the nation directly 
affected by the results of such loss. 

It would, perhaps, be possible, by a careful chemical 
survey of our soils, to determine both the actual and 
potential fertility of our entire country, and this knowl- 
edge, together with an accurate measure of the intelli- 
gence exercised in its use, would enable a prediction as 
to our future development, if present methods were con- 
tinued. That is, whether our land would become barren 
and worthless, as has been the case in many older coun- 
tries which at one time were quite as productive, or 
whether it would constantly increase in productiveness, 
even with continuous and profitable cropping, — although, 
as already pointed out, the present barrenness or sterility 
of a country formerly fertile may not be due entirely 
either to the natural or to the artificial loss of these 
constituents. 



Fertilizers 



SOURCES OF NATURAL LOSS OF NITROGEN 

Of the essential constituent elements, nitrogen is, in 
one sense, of the greatest importance ; first, because it is 
the one that is more liable to escape than the others, and 
secondly, because it is more expensive to supply arti- 
ficially than are the minerals. It is the most elusive of 
all the elements: to-day it may be applied to the soil, 
to-morrow it may be carried in streams to the ocean. 
It is also unstable — which is not the least valuable of 
its characteristics if properly understood : to-day it is 
an element of the atmosphere, to-morrow it is a con- 
stituent part of a growing plant, the next day the same 
element may exist as an animal product, and the day 
following it may be returned to the soil to feed the plant. 
It is more liable to escape than any of the others, because 
it is available as plant-food largely in proportion as it 
changes to a nitrate, and after it assumes that form it is 
seldom absorbed or fixed in the soil. Nitrogen in this 
form remains freely movable, and the probability of loss 
by leaching is increased in direct proportion to the lack 
of preventive measures used, or the presence of those 
conditions which favor leaching. The latter may be 
classified as follows : First, the amount and time of the 
rainfall ; secondly, the absorptive and retentive power of 
the soil and subsoil, due to their mineral and physical 
character ; and thirdly, the amount of vegetable matter 
(humus) acquired by the soil, which retards the passage 
of water. While the amount and time of rainfall can- 
not be controlled, its effect upon our soils in this direction 
can be largely governed if proper attention is given to 
correcting the other conditions, and these may be largely 
modified, if not entirely controlled. In the matter of the 



Natural Fertility of the Soil 9 

absorptive and retentive power of soils, it has been shown 
that if they are well supplied with vegetable matter and 
carefully cultivated, they retain and hold the plant-food 
constituents in a much greater degree than if devoid of 
humus and improperly managed, and also that the drain- 
age water from soils upon which crops are growing sel- 
dom contains more than the merest trace of nitrates. 
The loss of nitrogen through the operation of the forces 
of nature may, therefore, be reduced by the careful 
management of the soil. 

Importance of careful culture. 

The presence of suitable amounts of vegetable matter, 
and good cultivation, are conditions that are within the 
power of all farmers to provide, though it is sometimes 
impracticable to keep the land continuously covered with 
a crop ; and sometimes it is thought that the loss incurred 
through leaching because of the absence of a growing crop 
is more than balanced by the gain in other directions. 
For example, though losses of nitrates may occur, the gain 
in availability of the mineral constituents, phosphoric 
acid and potash, with the accompanying improvement 
in texture, due to the exposure of the soil to atmospheric 
influence, more than balances these losses, particularly 
during the winter, with its wide changes of temperature. 

Loss of nitrogen by drainage. 

It has been shown by carefully conducted experiments, 
both in this and other countries, that in a season of aver- 
age rainfall the drainage waters carry away from one 
acre, from uncropped soils only fairly rich in plant- 
food, as much as 37 pounds of nitrogen a year, while 
when continually cropped the drainage waters from the 



10 Fertilizers 

same soils contain practically no nitrogen. This differ- 
ence in the loss of nitrogen under the two conditions may 
not seem a great matter at the first glance, but a careful 
study of the bearing of this loss in its relation to crop 
production shows that it is really a serious matter. In 
the first place, the amount of possible loss annually is 
practically equivalent in nitrogen to the amount con- 
tained in two tons of timothy hay, or in one ton of either 
wheat, rye, oats, corn or buckwheat, quantities nearly 
double the average yield to an acre of these crops through- 
out our whole country ; and in the second place, that the 
nitrogen which is carried away by the drainage water is 
in the very best form for feeding the plant, or it would 
not have been lost, and thus its loss leaves the soil not 
only poorer in this constituent element, but poorer in 
the sense that the remainder of it in the soil is in a less 
useful form. Furthermore, if this nitrogen is to be re- 
turned to the soil in the same form, which is the cheapest, 
it would cost at present prices $6.85. 

Escape of nitrogen into the atmosphere. 

Another source of natural loss of nitrogen is its escape 
from the soil as gas into the atmosphere. This is due to 
the oxidation of the vegetable matter, or to " denitrifica- 
tion," which takes place very rapidly when soils rich in 
vegetable matter are improperly managed. The possi- 
bilities of loss in this direction are strongly shown by in- 
vestigations carried out at the Minnesota Experiment 
Station on "the loss of nitrogen by continuous wheat 
raising." The results of these studies show that the total 
natural loss of nitrogen annually was far greater than the 
loss due to the cropping. In other words, by the system 
of continuous cropping, which is universally observed in 



Natural Fertility of the Soil 11 

the great wheat fields in the Northwest, there were but 
24.5 pounds of nitrogen removed in the crop harvested, 
while the total loss to the acre was 171 pounds, or an 
excess of 146 pounds, a large part of which loss was cer- 
tainly due to the rapid using up of the vegetable matter 
by this improvident method of practice. Whereas, on 
the other hand, when wheat was grown in a rotation with 
clover, the gain in soil nitrogen far exceeded that lost or 
carried away by the crop. The continuous wheat- and 
corn-growing in the West, and of cotton and tobacco 
in the southern states, are responsible for untold losses 
in this expensive element of fertility, while in nearly 
every state of the Union, soils both rich and poor are 
suffering more or less from the effect of natural losses in 
this direction. 

THE NATURAL LOSS OF THE MINERAL ELEMENTS 

In the case of the minerals, phosphoric acid and potash, 
which exist in fixed compounds in the soil, the actual 
losses are undoubtedly very much less than is the case 
with nitrogen, since only traces of these constituents 
are ever found in solution in the drainage waters under 
ordinary circumstances; yet, because of the large quan- 
tity of water that passes through many of our soils, the 
total amount of these rendered soluble and carried away 
by this means is very great. Our great rivers carry in 
solution into the ocean tons upon tons annually of these 
elements of fertility, and it is an absolute loss, as there is 
no natural means by which these may be returned to the 
soil, as is the case with nitrogen ; and it is true, as in the 
case of the former, that the soil is not only absolutely 
poorer by virtue of the loss of its elements of fertility, 



12 Fertilizers 

but poorer in the sense that the immediate utility of those 
remaining is reduced. These silent and unseen forces 
constantly at work are reducing the content of these con- 
stituents in our soils to an alarming degree, and it is 
because they are unrecognized forces that the disastrous 
results of their activity are not fully appreciated, and, 
consequently, the best means for restoring them are not 
used. 

Losses due to mechanical means. 

A serious loss of all the fertility elements is also due 
to mechanical means. Aside from the amounts that the 
rivers of water are carrying in solution into the seas, im- 
mense amounts are carried in them in suspension. The 
results of this kind of loss are painfully evident ; in many 
of the southern states, and in sections where the forests 
have been removed and the land abandoned, the soils 
have been washed and gullied until not only the very 
best portions, but in some cases the largest portions, have 
been carried away. 

It is not, however, in the abandoned parts of the coun- 
try alone that these mechanical losses of constituents are 
of importance — they are more or less apparent on every 
farm, and are measured by the methods of management. 
Soils that are allowed to lie bare and fully exposed to the 
storms of wind and rain throughout the larger part of the 
year suffer the greatest loss, while from those which, on 
the other hand, have crops growing during a large part 
of the year, and which hold the soil particles together and 
prevent their easy movement, the losses are reduced in 
both the directions mentioned. The beneficial results de- 
rived from the use of good methods are cumulative ; the 
benefit is not only immediate, but continuous. 



Natural Fertility of the Soil 13 



ARTIFICIAL LOSSES OF FERTILITY 

In addition to these natural losses of fertility, there are 
the artificial losses of the constituents, or those due to 
the removal of crops. These, of course, necessarily ac- 
company all farming operations, and, provided that in 
the removal and sale of the constituents in the form of 
crops, the farmer has received a fair price for them, they 
are entirely legitimate. 

The sale of farm products is really in the last analysis 
a sale of actual constituents, together with a certain por- 
tion of the "condition" of the land, which is not readily 
measurable. That is, it is the constituents in the soil, 
together with the conditions surrounding it, that the 
farmer buys when he buys land. If an acre of land, con- 
taining within the reach of the roots of the plant, say, 
3000 pounds of nitrogen, 5000 pounds of phosphoric 
acid and 6000 pounds of potash, sells for $100, the seller 
receives the $100, not for so much dirt, but really for the 
constituents contained in it. The purchaser believes 
that, with the conditions surrounding them, he can con- 
vert them into products which he can sell and from which 
realize a profit. If in selling these amounts of the con- 
stituents in the form of land, a lower price to the acre is 
received, it is because the natural conditions which sur- 
round them, and which influence their utility, are less 
favorable, and a greater proportionate effort and expense 
are necessary to secure them in the form of salable prod- 
ucts. The difference in the price of land is not always 
due to the content of the constituents, but often to the 
conditions surrounding them. In many cases, the soil 
may serve simply as a medium in which plants can grow, 
and the content of the fertility elements is of minor im- 



14 Fertilizers 

portance. Such would be the case in the growing of 
market-garden crops near large cities, the location near 
the consumer being of greater importance, in the case of 
perishable crops of this sort, than the chemical character 
of the soil. In the larger number of cases, however, the 
natural fertility fairly measures the market price. At the 
price to the acre, and for the quantity of constituents here 
assumed, the buyer would pay at the rate of 1^ cents a 
pound for the nitrogen, and \ cent a pound each for the 
phosphoric acid and potash, and it now constitutes his 
capital stock. 

A comparison of the prices received for the fertility elements 
in different crops. 

A comparison of the prices paid for the constituents 
in land, with the prices received for the same constituents 
when contained in the different crops (disregarding for 
the moment the value of the "condition" of soil), will 
make clearer this matter of rational sale of constituents, 
which represents a reduction of our capital stock of fer- 
tility. For example, if wheat is raised which contains 
1.89 per cent of nitrogen, .93 per cent of phosphoric acid 
and .64 per cent of potash — or in round numbers, 38 
pounds of nitrogen, 19 of phosphoric acid and 13 of potash 
to a ton — and is sold for 80 cents a bushel, or $26.65 
a ton, the nitrogen sells in this form for 55 cents a pound, 
and the phosphoric acid and potash for 18 cents each a 
pound. That is, the 80 cents a bushel, or the 55 cents a 
pound, received for the nitrogen, and 18 cents for the 
potash and phosphoric acid, represent what has been 
received for a pound for the capital stock of these ele- 
ments, which at SI 00 an acre were purchased at the prices 
previously mentioned ; 1^ cents a pound for the nitrogen 



Natural Fertility of the Soil 15 

and \ cent a pound for the phosphoric acid and potash. 
The labor in raising the crop, the expense of harvesting 
and putting it upon the market, and the profit, must 
come out of the difference between what is paid and what 
is received. Naturally, as the ratio between the con- 
stituents contained in the products sold and the price 
received is increased, the rate of income to a unit of ex- 
haustion is increased, though in many cases the increased 
cost of the labor necessary is in proportion to the increased 
price received. This may be illustrated by a comparison 
on the fertility basis of the sale of wheat and milk. If 
milk, which contains on the average 12 pounds of nitro- 
gen, 4| pounds of phosphoric acid and 3^ pounds of 
potash to a ton, is sold for $1.50 a hundred pounds, the 
nitrogen is sold for $2 a pound, and the phosphoric acid 
and potash for, approximately, 70 cents a pound. In the 
sale of milk at this price, the rate of income to a unit of 
exhaustion is increased nearly four times over that of the 
wheat, though, because it is in one sense a manufactured 
product, the cost of labor to a unit of plant-food con- 
tained is largely increased. Again, if cream is sold, the 
prices received for the constituents are still further in- 
creased, while if the milk is made into butter, and that 
alone is sold, the prices received measure the expenses 
and profit, and the capital stock of fertility is not materially 
reduced, though it is in another form and in another place. 

Fertility content of cereals and vegetables. 

The losses of the constituents in the sale of cereals 
and grasses, corn, oats, wheat and hay are, too, rela- 
tively greater than in the sale of vegetables and fruits, as 
lettuce, celery, potatoes, tomatoes, sugar-beets, apples, 
berries and kindred crops, though in the case of the latter, 



16 



Fertilizers 



a higher degree of fertility is necessary in order to pro- 
duce maximum crops, and the cost of production is again 
proportionately greater. These facts strongly emphasize 
the necessity of a careful study of the relation of farm 
practice to the artificial losses of fertility. 

The artificial loss of fertility that may be incurred by 
the sale of crops is largely measured by the knowledge of 
the producer concerning the relation between the price 
received for the crop and the fertility contained in it, 
and thus removed when sold, and by his intelligence in 
adjusting his methods so as to reduce to a minimum the 
actual loss. 

The following tabular statement shows very clearly 
the differences in the losses of the constituents in the sale 
of different classes of plants : 

Fertilizer Constituents in Cereals and Vegetables 





Pounds in One Ton 




Nitrogen 


Phosphoric 
Acid 


Potash 


Cereals and Grasses 








Corn 


29.6 


12.2 


7.2 


Oats 


36.2 


15.4 


11.4 


Wheat 


34.6 


19.2 


7.0 


Rye 


32.4 


16.2 


10.4 


Timothy hay .... 


21.6 


7.0 


26.8 


Herd grass .... 


20.0 


7.0 


31.4 


Vegetables 








Carrots 


3.2 


1.8 


9.2 


Parsnips 


4.4 


3.8 


12.4 


Potatoes 


5.8 


1.6 


10.2 


Radishes 


1.6 


1.0 


8.0 


Beets (red) .... 


4.8 


1.8 


8.8 


Lettuce 


5.0 


1.6 


9.0 


Celery 


5.0 


4.0 


15.0 



Natural Fertility of the Soil 17 

Irrational farm practice. 

There are methods of practice which are entirely irra- 
tional, and contribute to the real losses of fertility. Farm- 
ing is unprofitable, not altogether because the land is 
exhausted, but because only those crops are grown which 
possess a high fertility value, and which have a low market 
price, and thus the prices received for the constituents 
in the crop are actually less than they cost in land and 
in labor ; and these methods of practice are not confined 
to farmers whose lands of inexhaustible fertility have 
been given them by a generous government, but are fol- 
lowed by farmers who annually purchase commercial fer- 
tilizers to supply the losses of fertility thus sustained. 

Where the conditions are such as to make it imprac- 
ticable to grow and sell crops, as such, of a low fertility 
value, the producer should endeavor to sell the manu- 
factured rather than raw materials, — that is, to so use 
his crude products as to lower the quantity of the con- 
stituents contained in those sold, which explains, in part, 
the greater success in the long run of a mixed husbandry, 
rather than single-crop farming. 

The artificial losses of our national capital stock of 
fertility are, however, not absolute, if the products are 
consumed in our own country, as more or less of the con- 
stituents contained in the crude products sold find their 
way back to the farm, either in the by-products of the 
mills, in sewage, in the manure from cities, or in various 
vegetable or animal wastes ; but when they are exported, 
the loss is absolute, and the amounts so disposed of are in 
some degree a measure of the rate of loss of the capital 
stock of fertility in our lands, though to these must be 
added the losses due to the improper use of manure and 
other waste materials. 



18 Fertilizers 



Losses in manures. 

It is natural to infer that proper losses of fertility are 
confined to the removal of the constituents in the sale of 
farm products, and that those contained in the materials 
not sold and in the feeds used upon the farm are again 
returned in part to the land. Theoretically this is correct, 
but the losses that do occur, particularly in the handling 
of manures, should not be overlooked. While it is im- 
possible to even roughly estimate the waste or loss of 
fertility due to the improper making or handling^ of 
manures, some idea may be obtained when the enormous 
amounts produced and the sources of possible loss are 
considered. 

If this enormous mass of waste material were properly 
used, it would go a great way toward increasing the 
present and immediate fertility of our soils, or in retard- 
ing the time of exhaustion, and it is quite pertinent to 
inquire if it is properly used. It has been demonstrated 
by experiments at Cornell Experiment Station that 50 
per cent of the total constituents in farm manures is 
liable to be lost by ill-regulated fermentation and by leach- 
ing; and further, careful observations and experiments 
show that the conditions in the larger number of barn- 
yards are such as to encourage the maximum loss by 
these means. It is morally certain that a large per- 
centage of the constituents contained in them are lost ; 
they never reach the right place on the farm. 

It is estimated that if but one-tenth of the present waste 
could be avoided, — and a very large part of it is prac- 
tically avoidable, and at a very slight expense, — the total 
amount of constituents that may thus be saved for further 
use would be more than equivalent to the amounts now 



Natural Fertility of the Soil 19 

purchased in the form of commercial fertilizers. This 
estimate is certainly conservative, and clearly demon- 
strates the serious drain upon our resources of fertility ele- 
ments, due to the lack of care in the handling of farm 
manures. 

The conditions, as here pointed out, not only suggest 
the need of imported plant-food, but that there are oppor- 
tunities for reducing this need by careful saving and use 
of the constituents that are subject to waste. 



CHAPTER II 

THE FUNCTION OF MANURES AND FERTI- 
LIZERS, AND THE NEED OF ARTIFICIAL 
FERTILIZERS 

While in a broad sense a manure or fertilizer may 
be regarded as anything that will increase the yield of 
a crop if added to the land, the chief function of ma- 
nures is to furnish nitrogen, phosphoric acid and potash. 

THE ESSENTIAL ELEMENTS OF FERTILIZERS 

These are called the "essential manurial elements," 
or "constituents," to distinguish them from the others 
that are needed by plants, because these three are con- 
tained in the crops removed in greater amounts than 
the others, and because they exist in the soil in much 
smaller amounts than the others. For example, culti- 
vable soils seldom contain too little iron or sulfur, or 
magnesium. These elements usually exist in quantities 
more than sufficient to supply all the needs of the plant 
for them, and, because they are required in such exceed- 
ingly small amounts, the soils are seldom exhausted of 
them. In addition to this property of supplying essen- 
tial manurial constituents, many substances useful as 
manures possess, however, a secondary function : they 
serve to indirectly increase the crop, but do not add directly 
to the potential fertility of soils. 

20 



The Function of Manures and Fertilizers 21 



NATURAL MANURES AND ARTIFICIAL FERTILIZERS 

Farmyard manure, and many other natural products, 
possess this second function in a marked degree, and 
the indirect manurial value of these is due largely to 
the good effect that the substances associated with the 
nitrogen, phosphoric acid and potash in them exert in 
increasing the crop. This good effect is observed in two 
directions. First, the vegetable matter contained in 
the natural manure improves the physical character of 
soils — those that are clayey and compact, by making 
them more open and porous, separating the particles, so 
that the water and air can penetrate more freely, and 
thus act directly upon the dormant or insoluble constit- 
uents that are contained in it; and those that are light 
and sandy, by filling up the open spaces, thus making 
them more compact. In the second place, the addition 
of vegetable matter to soils, even though it contains no 
essential constituents, improves it by enabling it to more 
readily and completely absorb and retain not only the 
water, but also the soluble essential constituents that 
may be added. The chief distinction between what are 
known as manures and what are known as fertilizers 
is the difference in respect to this secondary function. 
The manure possesses the two functions, the one to supply 
the essential constituents, and the other to assist plant 
growth by aiding in the improvement of those already 
contained in the soil, and this latter function it exerts in 
a marked degree ; while the fertilizer, as a rule, possesses 
but one, namely, that of furnishing plant-food. The 
indirect effect of the materials associated with the con- 
stituents in artificial fertilizers is seldom very useful, and 
sometimes may be harmful. 



22 Fertilizers 



DIRECT AND INDIRECT EFFECT OF MANURES 

It is obvious, therefore, that any substance which con- 
tains nitrogen, phosphoric acid or potash may serve 
as a direct manure, and any substance which contains 
no plant-food, but which possesses the power of improv- 
ing the physical character of soils, may also serve as a 
manure, though the one effect is quite distinct from the 
other. The first adds to the soil the essential constitu- 
ents ; the other helps to make the constituents already in 
the soil serve as food to the plant. 

The use of the one will tend to increase both the poten- 
tial and practical fertility in the soil, while by the use of 
the other the active fertility is increased as the potential 
fertility is decreased. That is, when actual plant-food 
is added in the form of nitrogen, phosphoric acid or potash, 
and crops are removed, the exhaustion of the soil is in 
proportion to the amounts of these removed over and 
above the amounts which have been added. Whereas, 
in the other case, when no plant-food is added, the exhaus- 
tion is measured by the amount of the constituents re- 
moved. It is clear, therefore, that the addition of only 
indirect manures has a tendency to rapidly reduce the 
fertility of soils of low natural strength, or those that do 
not possess large stores of food constituents, whereas, 
on soils that are rich in the fertility elements, the indirect 
manuring may result in an increased yield for a long 
period, though ultimately the soil will become exhausted 
— if not completely, to such a degree as to render further 
cropping by this method unprofitable. 

There are a number of substances which act in both 
capacities — directly and indirectly — and in order to 
understand thoroughly the value of such materials they 



The Function of Manures and Fertilizers 23 

must be studied from both points of view. Farmyard 
manure is an example. It contains nitrogen, phosphoric 
acid and potash, and possesses the power of improving 
the physical character of soils. Lime, generally consid- 
ered an indirect manure, may act in the capacity of a 
direct manure upon soils sufficiently lacking in this ele- 
ment. Other materials which act in both capacities under 
peculiar conditions are magnesia salts, iron salts, basic- 
slag, nitrate of soda and the like. 

UNAVAILABLE AND AVAILABLE PLANT-FOOD 

While, as already stated, any material containing 
either one or all of the three essential constituents, nitro- 
gen, phosphoric acid or potash, may serve as a direct 
manure in the sense that it increases the potential fer- 
tility of any soil, the value of the addition of such mate- 
rials will depend not so much on the amount, as upon 
the power that the plant may possess of acquiring it — 
and it is here that the difference between manures from 
natural sources and those from artificial sources is again 
quite manifest. That is, the fertility constituents in 
natural manures are in large part combined with others 
in the form of vegetable matter, and with the exception 
of potash, they are, when in this form, largely insoluble, 
and, therefore, cannot be used by the plants until after 
decay begins. Whereas, in artificial manures, the con- 
stituents may be not only soluble, but may be in a form 
in which the plants can take them up immediately. 
In the first case, the plant-food is said to be unavailable, 
and in the second, it is said to be available. 

Nitrogen, one of the chief constituents of manures, 
for example, exists in three distinct forms : (1) the or- 



24 Fertilizers 

ganic form, in animal or vegetable matter, derived from 
any form of life, which must first decay before it can serve 
as plant-food. (2) As the decay goes on ammonia is 
formed, and then (3) from the ammonia the nitrate is 
formed, which is the form in which plants take up the 
largest proportion of their nitrogen. This process is the 
direct result of bacterial activity and is known as nitri- 
fication. Inasmuch as products exist which contain 
nitrogen in these three distinct forms, it is possible by their 
use to control largely the feeding of the plant in respect 
to this element, while in the case of natural manures, 
the feeding of the plant with nitrogen depends upon 
conditions which cause its change from the organic 
into the other forms. As these conditions are variable, 
the problem of the economical feeding of plants 
with nitrogen, other things being equal, becomes a more 
difficult matter with the natural than with the artificial 
manures. 

Phosphoric acid also exists in different forms, the 
form measuring to a large degree its availability : the 
organic, in which the availability depends upon the 
rapidity of decay; and the soluble and immediately 
available form, — that is, the form that distributes 
everywhere, and which the plant can absorb immedi- 
ately it comes in contact with the roots. Commercial 
products exist which contain the phosphoric acid in these 
distinct forms. The user is therefore enabled to supply 
this constituent in such form as may best suit his crop and 
soil conditions. 

In the case of potash, distinct forms, as muriate, sul- 
fate and carbonate, also exist, though in the case of potash, 
the form in which it is combined exerts less influence 
upon the availability of the element to the plant than is 



The Function of Manures and Fertilizers 25 

the case with nitrogen and phosphoric acid. All of these 
forms are soluble, and can be readily absorbed. 

DANGER OF LOSS FROM THE USE OF SOLUBLE PLANT-FOOD 

The fact that the artificial fertilizer-products con- 
tain the constituents in such forms and combinations 
as to enable them to feed the plant immediately, also 
presents some disadvantages from the standpoint of 
economical use. This is particularly true in the case 
of nitrogen, for nitrogen, when applied in the form of 
nitrate, in which form it is taken up by the plant, does 
not combine to make insoluble compounds, but remains 
freely soluble. A great waste, therefore, may ensue from 
leaching into the lower layers of the soil and beyond the 
roots of plants, or into the drains, and the plant-food be 
carried away, unless care is exercised both as to the amount 
and the method of application. With soluble phosphates, 
the danger of loss is much less than with nitrogen. If 
these are applied in too large quantities to meet the needs 
of the plants, or under improper conditions, their tend- 
ency is not to remain soluble, but to revert to their 
original and insoluble form. The main fact, however, 
is that in artificial fertilizers we may have the constit- 
uents in distinct and separate forms, which permits the 
feeding of the plant, rather than the feeding of the soil ; 
and this is usually, and must necessarily be, the case when 
natural manure products serve as the entire source of the 
added fertility. For example, nitrogen may be supplied 
in artificial fertilizers in three forms, each form being dis- 
tinct and separate from the other, and each giving up its ni- 
trogen to the plant at a different time, supplying its needs as 
required by growth, in which case the danger of loss is small. 



26 Fertilizers 

THE USEFULNESS OF A FERTILIZER CONSTITUENT DOES 
NOT DEPEND UPON ITS ORIGINAL SOURCE 

It should be remembered, too, that artificial manures 
or fertilizers supply plant-food just as well as other and 
more common products. The fact that the food exists 
in substances other than those which are familiar to the 
farmer, is no evidence that it may not be quite as good, 
or even better, than when contained in his home-made 
products. It is not the outward appearance of a sub- 
stance, but the kind and form of the elements contained 
in it, that measures its value as a fertilizer. 

For example, the nitrogen that may be applied in 
the form of a commercial fertilizer exerts no different 
function in the plant than that which may be acquired 
from the original soil, or from materials that have recently 
been obtained from that soil, and again returned as yard 
manure. The same is true of phosphoric acid and 
potash. In their concentrated, artificial forms, they serve 
to feed the plants in exactly the same way, and exert the 
same function in them, as those contained in the soils 
themselves, or that may be contained in wood ashes, or 
materials more familiar, or of more common occurrence. 
The form in which they exist when applied does not 
necessarily imply that they are stimulants rather than 
food, though frequently, because of their form, the plants 
are able to absorb them more readily, and thus by their 
rapidly increased growth, encourage a belief that an un- 
due stimulating effect accompanies their use. The fa- 
mous experiments of Lawes and Gilbert, at Rothamsted, 
England, teach this one thing very emphatically ; viz., 
the efficiency of chemical fertilizers as compared with 
yard manures. 



The Function of Manures and Fertilizers 27 



USE OF FERTILIZERS 

While manures in the ordinary sense, and even mate- 
rials which are now included under the head of artificial 
manures, such as ground bone and wood ashes, have been 
used for a very long time, the use of artificial products 
in a true sense is of comparatively recent origin. The 
first use of genuine artificial fertilizers dates from the pub- 
lication of Baron von Liebig's book, " Organic Chemistry 
in its Application to Agriculture and Physiology," in 
1840 ; yet for a long time after this date the increase in 
their use was very gradual. The very excellent, and at 
that time surprising, results which were obtained from 
the application of Peruvian guano, one of the first prod- 
ucts to receive attention, manifestly increased the 
interest in the subject also. These good results were 
observed more particularly on the continent of Europe, 
where the lands had been under cultivation for a long 
time. The use in America, previous to 1860, was quite 
insignificant. Since the work of Liebig, a very great 
amount of study has been given to the subject, both in 
reference to the essential character of the various mate- 
rials, and their influence upon the production of plants. 
Perhaps no other single subject relating to agricultural 
science has been studied more fully than the question of 
the use of artificial manures; and these studies have 
resulted, not only in the discovery of new materials, but 
in their better preparation for use as plant-food, which 
greatly increased their effective use. There is no ques- 
tion connected with agriculture which is of greater direct 
and practical importance, particularly in those countries 
which have been depleted of their active fertility by the 
means mentioned, or in which the conditions are as pre- 



28 Fertilizers 

viously outlined, than definite knowledge of the true 
principles which govern in the profitable use of com- 
mercial fertilizers. Yet, notwithstanding all the good 
results thus obtained, and their great practical importance 
to agriculture, much still remains to be done, particu- 
larly in the establishment of fundamental principles. 

While it is desirable that in a work of this kind scien- 
tific discussions should be avoided as far as possible, and 
the subject made as plain as is practicable to those using 
fertilizers, it is necessary to their right use that those who 
apply them to their land should have a very clear concep- 
tion of the underlying principles, so far as they are known, 
in order that they may intelligently increase their pro- 
duction, and thus reap a profit. Definite knowledge is 
an important factor in determining their profitable use. 

THE NEED OF ARTIFICIAL FERTILIZERS 

The considerations in the previous chapter explained 
in part, and in a broad, general way, the necessity for the 
use of commercial fertilizers. The conditions of farming 
in this country have greatly changed in the past thirty 
years, and these changes have, perhaps, a still more 
important bearing in showing the need of imported fer- 
tility than the conditions already discussed. The first 
direction in which important changes have taken place 
is in the increased cost of farm labor and in the relatively 
low prices now received for the staple crops, the cereal 
grains, cotton and tobacco. 

The cost of production to a unit of income is increased. 

The cost of labor is increased because proportion- 
ately higher wages are now paid, and because the labor 



The Function of Manures and Fertilizers 29 

now obtainable is on the whole less efficient, being per- 
formed more largely by those untrained for their work, 
rather than by the owner and his sons; and this in- 
creased cost of labor makes the cost of growing the staple 
crops much greater in proportion to their market value 
than was formerly the case, though there are, of course, 
exceptions. 

For example, harvest wages throughout the eastern 
part of the country, at any rate, were in the sixties regu- 
lated somewhat by the price of wheat. When wheat was 
$3 a bushel in the eastern states, the daily wage was $3. 
Now the daily wage in the east ranges from $2 to $2.50 a 
day, while the price of wheat does not often exceed $1 a 
bushel, and the price received is frequently much lower. 
The wages for other kinds of farm work are proportion- 
ately the same in reference to present prices of products. 
During the past twenty-five years the cost of labor has 
increased materially and remains constant regardless of 
the nature of the work, character of farming, crop grown 
or season. This condition, considered in connection 
with the important fact that the total cost of crop to the 
acre is practically the same, whether the yield is high or 
low, exerts a decided influence in determining profits, 
particularly on land of medium fertility. The cost of 
preparing the land for the seed, the cost of seed and the 
seeding and harvesting are the same for a crop of wheat, 
whether the yield is 10 or 30 bushels an acre; but this 
cost will not permit a profit from the 10-bushel yield, 
because the cost to the bushel is too largely increased. 
The same considerations hold true for a number of other 
crops. Small yields of these relatively low-priced crops 
cannot be profitably produced with the present high price 
of labor; and it has been shown, furthermore, that land 



30 Fertilizers 

which is not in a high state of fertility will not produce 
large yields. 

Many soils, especially those in the eastern and south- 
ern sections of our country, which were not originally 
very fertile, and which have been cropped for a long 
time, show abundant evidence of the need of fertility from 
sources outside of the farm, in order that maximum crops 
may be produced. The aim should be, therefore, to make 
the conditions of soil better, and, if possible, so perfect 
as to guarantee against any lack of food during the grow- 
ing period, and thus make the conditions of climate and 
season, rather than the soil, the measure of the crop. 
That is, as far as practicable, the yield that it is possible 
to obtain in a given locality should be the aim of the 
farmers in that locality. In order to make the conditions 
of soil perfect in this respect, the fertility elements must be 
added, though indirect manuring, in the form of better 
cultivation and better use of the waste products of the 
farm, are also to be encouraged. 

A greater demand for special crops. 

In the second place, farming to-day consists of much 
more than the simple production of the staple crops. 
Changed conditions are shown very clearly in the increased 
demand for medicinal plants, nuts, nursery stock, mar- 
ket-garden products, fruits, and special poultry, dairy and 
swine products. Not so many years ago the staple 
crops already described were practically the only ones 
raised and sold from the farm. 

For example, the growing of vegetables and fruits 
was limited. They were regarded as luxuries, and the 
area given to them was, on most farms, only sufficient 
to meet the needs of the home. These were not regarded 



The Function of Manures and Fertilizers 31 

as crops in the same light as the others, and were seldom 
the source of direct income. At the present time, vege- 
tables and fruits are regarded as necessities in every home, 
and their use is not confined to the season in which they 
can be provided in the immediate vicinity of the cities 
or towns where they are used ; they are drawn from points 
far distant, and the demand is such as to require the use 
of wide areas in order to supply the needs. The growing 
of market-garden crops and fruits is now the basis of 
specific agricultural industries which have assumed large 
proportions. 

Much progress has been made, too, in the develop- 
ment of methods of practice in these lines of farming, 
and the experience gathered has shown that even our 
most fertile soils in their natural conditions contain 
too little active food to insure maximum yields of crops 
of the best quality; in these lines of farming, too, easi- 
ness and edible quality of products, which are influenced 
by the food supply, are important factors in determining 
the profits to be derived. The areas now necessarily 
devoted to these crops are so great that soils of a high 
natural fertility, even if natural fertility alone could be 
depended upon, are too limited to meet the demand and 
enable a profit, especially in the vicinity of good markets ; 
in other respects a good location, because permitting of 
cheap distribution, is an important factor. 

Farm manures are inadequate. 

Farm manures might meet the needs for the staple 
crops, as they are well adapted in many respects for 
the purpose, but, under present systems of manage- 
ment, the amount is not sufficient to meet the annual 
losses from the sale of crops, much less to provide an 



32 Fertilizers 

increase, and the only other source is an artificial supply, 
or commercial fertilizers. For the special crops already 
described, the natural manures of both farm and city 
are not only not sufficient, but, because of their character 
and composition, are not well adapted to meet economi- 
cally the entire demands of the plants. In the first place, 
they are bulky, and thus expensive to handle. In the 
second place, the fertility elements contained in them are 
not in good proportion ; they are, as a rule, poor in the 
mineral elements and rich in nitrogen, and their use in 
sufficient amounts to meet the needs of the plant for the 
mineral elements results in a waste of the nitrogen. Third, 
the constituents contained in them are not in sufficiently 
active forms to provide for a rapid and continuous growth 
without an excessive application, which frequently results 
in a serious waste not only of the nitrogen, as already indi- 
cated, but, in the case of many crops, an abnormal growth 
of vine or stalks, which may seriously injure the market- 
able quality of the crops. For many crops, economical 
production requires that the natural manures be supple- 
mented by artificial supplies, by means of which the form 
and amount of the individual constituent can be regu- 
lated to meet the needs of the various plants. 

The growing importance of fruit-growing. 

In fruit-culture, an industry of growing importance, 
it has been found that soils in their natural condition, 
while they may be well adapted in other respects, — that 
is, possess a suitable physical character for the growth 
of this class of crops, — contain insufficient amounts of 
the mineral constituents which are required in order 
that continuous and large crops of perfect fruit may 
be secured. To supply this deficiency farmyard manure 



The Function of Manures and Fertilizers 33 

would cause in many cases an over-supply of vegetable 
matter containing nitrogen, which for these crops is fre- 
quently followed by disastrous results, not only causing 
an abnormal growth of leaf and wood, but inducing it at 
such periods of the year as to materially interfere with the 
proper ripening of both the wood and the fruit. By the 
use of artificial fertilizers, these difficulties may be largely 
overcome. 

WILL IT PAY TO USE FERTILIZERS? 

It must be confessed that to give a definite and positive 
answer to this question, with our present state of knowl- 
edge, is a difficult matter, if not well-nigh impossible, 
because of the very large number of varying conditions 
that are involved. 

Usually such a question cannot be answered in a 
rational way without first securing definite information 
concerning the conditions under which they are to be 
applied, as, for instance, the character of soil, whether 
a sand, clay or loam; situation in reference to mois- 
ture, whether too dry or too wet; the kind of subsoil, 
whether a loose, open sand or gravel, a medium clay or 
a tight, impervious hard-pan; the character of the pre- 
vious treatment and cropping, whether the land has been 
manured or fertilized, whether good cultivation has been 
practiced, whether leguminous crops have been grown to 
any extent, whether the produce raised has been sold, 
or fed on the land ; whether the object of the growth has 
been for immature produce and for early market, and 
artificial growth demanded, or whether for maturity, 
when the natural tendency has simply been assisted and 
the development normal in all directions. 



34 Fertilizers 

If these questions are answered truthfully and in 
detail, a scheme of fertilization may be adopted that 
will enable the farmer to secure the greatest returns for 
the plant-food applied. 

That the returns from the use of fertilizers are fre- 
quently unprofitable is not always the fault of the fer- 
tilizer, and this point may be illustrated by the following 
typical case : One farmer applies plant-food, his crop is 
doubled or trebled, and a reasonable profit is secured. 
Another farmer applies the same amount and kind of 
fertilizer under similar natural conditions of soil, and he 
receives no benefit. The same climatic conditions sur- 
rounded the crops of both : the sun that warmed the soil 
and furnished the energy necessary for the production of 
the largely increased crop is the same sun that shone upon 
the small crop ; the air that furnished a large proportion 
of the food for the one is the same air that surrounded 
the other; the rains that moistened and assisted in the 
solution and circulation of plant-food for the one were 
the same for the other. Why, then, the difference in 
results? In one case the natural agencies, sun, air, 
and water, were assisted and enabled to do their maximum 
work, while in the other, they were prevented from exer- 
cising their full influence. Physical conditions of soil 
were imperfect, due to careless plowing, seeding, cultiva- 
tion and cropping. 

In other words, the profit from the use of plant-food 
is measured to a large degree by the perfection of soil 
conditions, which are entirely within the power of the 
farmer to control. The production possible from a defi- 
nite amount of plant-food can be secured only when the 
conditions are such as to permit its proper solution, 
distribution and retention by the soil. 



The Function of Manures and Fertilizers 35 

The fact that fertilizers may now be easily secured, 
and the ease of application, have encouraged a careless 
use, rather than a thoughtful expenditure, of an equivalent 
amount of money or energy in the proper preparation of 
the soil. Of course, it does not follow that no returns 
are secured from plant-food applied under unfavorable 
conditions, though full returns cannot be secured under 
such circumstances. Good plant-food is wasted, and the 
profit possible to be derived is largely reduced. 

Again, because farming, in its strict sense, is the 
conversion of three essential elements into salable prod- 
ucts, the time to apply plant-food must be governed 
largely by its cost and the kind of crop upon which it 
is applied. 



CHAPTER III 
NITROGENOUS FERTILIZERS 

Nitrogen is the most expensive constituent of fertilizers, 
and, all things considered, it is one of the most useful. 
Nitrogen exists in nature as a component of the air, and 
though quite as necessary to vegetation as carbon or 
oxygen, — which also exist in the atmosphere, and which 
are readily acquired by all plants, — all plants do not 
have the power of acquiring nitrogen from this source. 
This power seems to be limited to a class of plants called 
Leguminosse, to which belong the various clovers, peas, 
beans, vetches and a number of others. The important 
farm crops belonging to the other botanical groups of plants 
obtain their nitrogen largely, if not altogether, from the soil. 

Vegetable or animal matter containing nitrogen may 
serve as a source of nitrogen to plants, though it cannot 
feed them with this element to any extent until it decays 
or rots. In order to obtain a clear conception of the use 
of nitrogen as a fertilizer, one should understand the need 
of plants for it, what is meant by form of nitrogen, and the 
sources from which the various forms may be derived, 
as well as the relative agricultural or crop-producing value 
of the nitrogen in existing commercial forms. 

WHAT IS MEANT BY FORM OF NITROGEN? 

Strictly speaking, form of nitrogen has reference to its 
combination or association with other chemical elements, 
though sometimes the term " form " is used to indicate rate 

36 



Nitrogenous Fertilizers 37 

of solubility, which also measures to some degree avail- 
ability, since it happens that soluble forms of nitrogen 
are really more available than the insoluble forms, though 
neither the soluble nor insoluble forms show the same rate 
of availability ; that is, a pound of soluble nitrogen is not 
equally available from whatever source derived, and a 
pound of insoluble from one source may be much more 
available than a pound from another. The form in which 
nitrogen exists in vegetable and animal matter is called 
the "organic form," because it is associated with other 
constituents, as carbon, hydrogen and oxygen, which are 
necessary to make the substances that constitute animal 
or vegetable matter. The term "organic," as applied to 
nitrogen, covers a whole series of substances, and does 
not indicate a uniformity, either in content or quality of 
the nitrogen, as is the case with distinct chemical com- 
pounds; hence, associated with the knowledge of form 
of nitrogen, when it exists in organic products, must be a 
knowledge of whether the material contains a very con- 
siderable amount of nitrogen, and whether it is likely to 
be readily changed, and thus become available as food for 
plants. 

Any nitrogenous vegetable or animal matter may serve 
as a fertilizer, though organic nitrogen in commercial fer- 
tilizers is usually obtained from products relatively rich 
in this constituent, and it is only these that can be used 
to advantage in making what are known as "high-grade 
fertilizers." The leading animal substances of this class 
are now mentioned. 

DRIED BLOOD 

One of the most important products from which organic 
nitrogen is derived for commercial fertilizers is dried blood. 



38 Fertilizers 

It is important not because the supply is large and the 
price low, but because it is one of the most concentrated, 
one of the richest in nitrogen of the organic nitrogenous 
fertilizing materials. It is one of the best, since its physi- 
cal character is such as to permit of its very rapid decay 
in the soil during the growing season. This tendency to 
decay rapidly is plainly apparent, when it is remembered 
that blood as it exists in the animal is in fluid form, and 
naturally any material which is sufficiently finely divided 
to permit of its ready flow, and is not associated with any 
hard or fibrous material, possesses characteristics which 
enable a rapid breaking down when subjected to the 
proper temperature and moisture conditions which 
promote decay. 

Dried blood for fertilizing purposes is chiefly obtained 
from the large slaughtering establishments. The markets 
recognize two distinct kinds, red and black. The former 
is carefully dried with hot water and contains 13 to 14 
per cent of nitrogen. It is uniform in composition and 
because of its quality commands the higher price. It 
contains only traces of phosphoric acid. The market prod- 
uct is standardized and guaranteed to contain 16 per 
cent ammonia. The latter — black blood — is dried at a 
higher temperature with less care, which gives it a darker 
color and leathery character. It also contains consider- 
able impurities, such as bone. It contains from 6 to 10 
per cent of nitrogen and often as high as 4 per cent of 
phosphoric acid. In this case, also, the market product 
is standardized and guaranteed to contain 12 per cent of 
ammonia. 

The red blood is considered a high-grade fertilizer 
material, uniform in composition, high in nitrogen and 
of excellent mechanical texture. The black blood, while 



Nitrogenous Fertilizers 39 

considered better than many other organic nitrogenous 
materials, is less concentrated and less uniform. It is un- 
fortunate from the farmer's point of view that the supply 
of these materials is decreasing so rapidly. 

DRIED MEAT OR MEAL, AZOTIN, AMMONITE OR ANIMAL 

MATTER 

Dried meat or meal, azotin, ammonite or animal matter, 
are terms applied to practically the same product produced 
at rendering establishments, where the different portions of 
dead animals are utilized. These are subjected to treat- 
ment, usually dried and extracted with steam, for the 
purpose of securing the fat, though formerly, and even 
now, a large portion of this product is obtained from the 
beef extract factories. When relatively pure it contains 
13 to 14 per cent of nitrogen and compares favorably with 
blood. When the use of fertilizer was less and the supply 
relatively greater this was an important product. To- 
day it is seldom heard of and the market does not recognize 
it as such. 

This product, very limited in supply, is reasonably uni- 
form in composition, containing as high as 12 per cent of 
nitrogen, and ranks among the high-grade materials. 
It is considered superior to leather, wool or hair. 

DRIED AND GROUND FISH, OR FISH GUANO 

Ground fish is obtained from two sources : first, from 
the offal, largely bones and skins, of fish packing or canning 
houses ; and second, from the fish pomace resulting from 
extraction of the oil from the Menhaden. The latter 
product is richer in nitrogen and is more uniform in char- 
acter than the wastes from the packing houses. Dried 



40 Fertilizers 

ground fish from this source contains from 7 to 8 per cent 
of nitrogen, and from 6 to 8 per cent of phosphoric acid. 
The former, owing to the varying proportions of bone, 
skin and flesh contained in it, varies widely in its content of 
nitrogen. Fish, besides affording a considerable supply of 
nitrogen, is also regarded as a good source of this element, 
ranking in availability well up to blood. 

The use of these materials is more common along the 
coast, where fishing is an important industry. The supply 
of fish pomace is to a marked degree regulated by the 
abundance of Menhaden, which varies greatly from year 
to year. More profitable use may be made of these prod- 
ucts if applied a few days before planting upon soils 
which present conditions favorable to decomposition. 

TANKAGE 

Tankage is a highly nitrogenous product, and consists 
chiefly of the dried animal wastes from the large abattoirs 
and slaughtering establishments. It is variable in its 
composition, since it includes the otherwise unusable 
parts of the carcass, as bone, tendons, flesh, hair and the 
like. The portions of this from the different animals not 
only vary in their composition, but they are used in vary- 
ing proportions, which naturally results in an extremely 
variable product. What is known as "concentrated 
tankage," which is obtained by evaporating the fluids 
which contain certain extractive animal matter, is the 
richest in nitrogen, and is more uniform in character than 
the others; and because of its fineness of division and 
physical character, the nitrogen contained in it is also more 
active than in the other forms. Two distinct kinds of 
tankage can, therefore, be obtained : first, concentrated 



Nitrogenous Fertilizers 



41 



tankage, which is the richer in nitrogen, ranging from 10 
to 12 per cent, and which contains very little phosphoric 
acid ; and second, crushed tankage, which is of several 
grades, ranging from 4 to 9 per cent nitrogen, and from 
3 to 12 per cent of phosphoric acid. Products are some- 
times sold as tankage, which contain much more than the 
maximum of phosphoric acid and less than the minimum 
of nitrogen here given, in which case they are to be classed 
with bone, rather than with tankage. Tankage varies 
so much, both in its content of phosphoric acid and nitro- 
gen, that in the trade it is always sold on the basis of its 
composition. The percentage of nitrogen and phosphoric 
acid is distinctly stated, and because it contains very con- 
siderable amounts of phosphoric acid, its commercial value 
is not wholly based on its content of nitrogen, as is the case 
with dried blood, dried meat and concentrated tankage. 
The market recognizes several distinct grades indicated 
by the following guarantees : 



Percentage 
of Ammonia 


Percentage of B. P. of L. 


Percent- 
age of 
Nitrogen 


Percent- 
age of 
Phos- 
phoric 
Acid 


11 

9 

7 
7 


20 equivalent to 
20 equivalent to 
30 equivalent to 
15 equivalent to 


9.0 
7.4 
5.8 
5.8 


9.15 

9.15 

13.75 

6.80 



Care should be taken in the purchase of tankage be- 
cause it is sometimes mixed with garbage tankage, a 
material less valuable and more variable. Adulterations 
of this kind are not easily detected. They are more 
common in the less concentrated tankage products. 



42 Fertilizers 

GARBAGE TANKAGE 

While this material is considered a low-grade product, 
it is, nevertheless, important because the supply is in- 
creasing annually. It is manufactured from kitchen 
wastes of the cities, sometimes by drying, sometimes by 
partial charring, but more often it is a by-product after 
treatment to extract oils and greases. However derived, 
it is very variable in composition and its value as a fer- 
tilizer differs with its content of the elements of plant-food. 
It is now used to considerable extent in the manufacture 
of commercial fertilizers and sometimes as an absorbent 
in stables, but for this purpose it lacks the desired qual- 
ity of cleanliness and often carries disagreeable odors. 
Analyses show that it may contain as high as 2.5 to 3 
per cent of nitrogen, 1.5 to 3 per cent of phosphoric acid 
and .75 to 1.5 per cent of potash. 

LOW-GRADE NITROGENOUS PRODUCTS 

Other products which contain a high content of nitrogen 
are frequently used. These, because of their low rate of 
availability, constitute a separate and distinct class. 

Horn meal, or ground horn, is reasonably uniform in its 
composition or content of nitrogen. It contains as high 
as 10 or 12 per cent of nitrogen, but it is slow to decay 
when used in its natural state, and, therefore, is not re- 
garded as an economical source of this element, unless 
it can be obtained at a low price. 

Leather meal is another product which is rich in nitrogen, 
but which is so slow to decay that its use in the natural 
state is not recommended. One object in making leather 
is to render it resistant to the conditions which promote 



Nitrogenous Fertilizers 43 

decay, and ground leather may remain for years in the 
soil in an unchanged condition. 

Wool and hair waste are also products which exist in 
considerable quantities, and while variable in composi- 
tion, are frequently rich in nitrogen, but they are classed 
with leather because of their slow activity. Their me- 
chanical form, coarse and bulky, makes it impossible 
to use them to advantage in the manufacture of fertilizers 
without previous treatment. The use of these materials, 
untreated, can only be regarded as desirable when they 
may be obtained at a very low cost. When dissolved 
with acid, or treated in such a way as to render them 
more immediately available, they may be used to ad- 
vantage, though the cost of such treatment is usually 
so great as to make it impossible to thus improve their 
form and still be able to compete commercially with 
the other nitrogenous products. 

VEGETABLE NITROGENOUS PRODUCTS 

Cotton-seed meal is one of the best organic nitrogenous 
fertilizing materials derived from vegetable life. When 
oil is extracted from cotton-seed, the residue is ground 
fine and sold as a food for cattle and as a fertilizer. Be- 
cause it is highly valued as a food for cattle, it has been 
standardized to contain 38 to 42 per cent protein, equiva- 
lent to 6 to 7 per cent nitrogen. It contains besides the 
nitrogen often as much as 3 per cent of phosphoric and 
2 per cent of potash. When mixed with hulls the per- 
centages of the elements of plant-food are lower. Tests 
made show that it ranks with blood in the availability 
of its nitrogen. Its use as a fertilizer is confined largely 
to the southern states, where cotton is a staple crop, and 



44 Fertilizers 

it may be secured in abundance without cost of trans- 
portations. Furthermore, its use as a food for cattle is 
becoming more thoroughly understood and appreciated 
so that its use as a fertilizer is decreasing. 

Linseed meal is a material somewhat similar in 
character to cotton-seed meal. It contains on the 
average 5.5 per cent of nitrogen. The demand for 
this product for feeding purposes at good prices makes 
it, however, an expensive source of nitrogen. 

Castor pomace, the waste resulting from the extraction 
of oil from the castor bean, is also a valuable nitrogenous 
fertilizer. It contains, on the average, 6 per cent of this 
element, and decays rapidly in the soil. This product 
differs from the cotton-seed and linseed meal, in that it is 
not useful as a cattle food. Practically its only use is 
as a fertilizer. 

Vegetable pomaces. — There are a number of pomace 
materials of local interest, including apple pomace, tomato 
pomace, pumpkin pomace, cranberry pomace and the 
like, which are used to a considerable extent by a few 
individual farmers. These materials are very variable 
in composition. They are usually used without drying 
and the content of moisture is almost never constant. 
Most of these products are derived from fruits or vege- 
tables very acid in character and the acid contained is 
often in large enough quantities to be injurious unless 
composted with dirt and slaked lime. 

NATURAL GUANOS 

A series of nitrogenous products which constitute still 
another separate class, consists of the various natural 
guanos. From its derivation the word " guano " means 



Nitrogenous Fertilizers 45 

dung, and it is probably one of the oldest materials used 
as a fertilizer. Its use dates back to the twelfth century, 
but it was not until the middle of the nineteenth century 
that its value became generally appreciated. The first 
shipments were made from Peru to European ports late 
in the year of 1840. The use of these products spread 
rapidly and were considered a valuable source of nitrogen, 
though at the present time they are not commercially 
important, owing to the practical exhaustion of the best 
supplies. Of the guanos, the product obtained from 
Peru, or from the islands on the coast of that country, 
is the richest in nitrogen. It is derived from the excre- 
ments and bodies of sea-fowls. 

When the deposits occur in regions which are warm and 
with little rainfall, they are high in nitrogen, especially if 
considerable time has elapsed since their formation. 
Where rainfall is more plentiful, even occasional, the 
nitrogen is readily changed by microorganisms to soluble 
forms which are leached away together with the potash 
salts, leaving a product low in nitrogen and high in phos- 
phoric acid. The first product usually contains from 12 
to 14 per cent of nitrogen and from 10 to 12 per cent of 
phosphoric acid, whereas the second product contains 
from 5 to 8 per cent of nitrogen and from 20 to 25 per cent 
of phosphoric acid. It must be remembered that guanos 
are variable and each successive consignment shows a 
different composition. In fact, the composition of these 
materials is of a very complex character. The nitrogen 
exists largely as ammonia, combined with oxalates, 
urates, humates, sulfates, phosphates, carbonates, and to 
some extent in purely organic form. In these forms the 
nitrogen is quickly available, and marvelous results are 
obtained from their use. 



46 Fertilizers 

There are many other deposits of guano, but none has 
been found which are so valuable as the Peruvian. 
Ichaboe guano, for example, is at present exported, 
though it is a fresh deposit, and is annually collected for 
shipment. Bat guano found in caves in Mexico and in 
some of the southwestern states is another example. 
Both are inferior to Peruvian guano. They contain 
less nitrogen and a very considerable amount of insoluble 
matter, though the nitrogen is usually in a good form. 
In the case of the latter, a considerable portion exists 
as a nitrate. Owing to the very excellent results that were 
obtained from the early use of guanos, many attempts 
have been made to improve the lower grades obtainable at 
the present time, by the addition of nitrogenous matter 
of a higher rate of availability. These rectified or 
fortified guanos, while containing nitrogen in good forms, 
cannot entirely substitute the original guanos, owing to 
the impossibility of adding forms identical with those 
existing in the natural product. That is, the total con- 
tent of nitrogen in a rectified guano may be the same as 
in the genuine product, though the special forms and their 
proportions cannot be simulated. The distinctive value 
of the natural guanos is due to the fact that the nitrogen 
existed in a number of different soluble compounds, 
which became available at different times in the soil, 
and thus constantly fed the plant with this element. 
The fact that nitrogen guanos gave such good results is 
an evidence of the advantage of introducing different 
forms into artificial mixtures. 

It is argued that because of the very great value of 
guanos, which consist very largely of the excrement 
of fowls, that droppings of pigeons, particularly, and of 
domestic fowls should also possess a high value, and for 



Nitrogenous Fertilizers 47 

this reason a rather fictitious value has been fixed upon 
these products. These products differ very materially 
from natural guanos, and it is due probably both to the 
character of the food eaten by the domestic fowl, and to 
the different methods by which the material is obtained. 
The birds producing the guanos feed largely upon fish, 
a highly nitrogenous food, resulting in an excrement 
richer in this element than that from the domestic bird, 
feeding largely upon vegetable matter ; and, besides, the 
former were accumulated in a hot, dry climate, which 
quickly absorbs the moisture contained in the fresh 
droppings, thus leaving it in a much drier state than is 
the case with the domestic product. 

MECHANICAL CONDITION SHOULD BE CONSIDERED 

It will be observed from the foregoing brief description 
of the chief sources of organic forms of nitrogen, that a 
very wide variation occurs both in the composition or 
content of nitrogen in these products, and in the avail- 
ability of their nitrogen, or rapidity with which, under 
similar conditions, it is given up to plants. The fact 
that a substance contains nitrogen in considerable amounts 
and in an organic form, then, is not a sufficient guide as 
to its usefulness. Its mechanical condition, or physical 
form, must also be taken into consideration, and, other 
things being equal, the tougher and denser the substances, 
the longer the time required to decay, and hence the more 
slowly will the material feed the plant. 

ammonia compounds. See Fig. 1, Plate 1. 

As already stated, nitrogen does not feed the plants 
in organic forms ; it must first decay. The first prod- 



48 Fertilizers 

uct of the decay of a nitrogenous organic substance 
is ammonia, a combination of two elements, hydrogen 
and nitrogen. As the organic animal or vegetable sub- 
stance which contains carbon, hydrogen, oxygen and 
nitrogen in combination breaks up, the carbon combines 
with part of the oxygen to form carbonic acid; part of 
the hydrogen also combines with oxygen to form water, 
and the nitrogen combines with hydrogen to form am- 
monia. Yet even in this form, plants do not absorb it 
freely. Ammonia is in a better form than the organic 
material, because, in the first place, it is soluble in most 
of its combinations with other substances, and is thus 
readily distributed in the soil, and in the second place, 
it is very liable to change. That is, its future availability 
is no longer dependent upon any mechanical or physical 
form; every portion or pound of ammonia is as good as 
any other portion or pound. Ammonia, however, does 
not occur as a natural product, like the organic forms, 
blood, meat and fish. Commercial forms are the result 
of a manufacturing process, and they may exist as dis- 
tinct chemical substances; as sulfate of ammonia, in 
which case the ammonia is combined with sulfuric acid; 
as chlorid of ammonia, in which case it is combined with 
hydrochloric acid ; as nitrate of ammonia, in which case 
it is combined with nitric acid ; and as carbonate of am- 
monia, in which case it is combined with carbonic acid. 
Sulfate of ammonia is a chemical salt which, when pure, 
contains 21.2 per cent of nitrogen. In commercial 
forms, however, it usually contains about 20 per cent 
of nitrogen. It is obtained from the dry distillation of 
animal bone in the manufacture of bone-black, from the 
distillation of coal in the manufacture of illuminating 
gas, and from coal in the manufacture of coke. The 



Nitrogenous Fertilizers 49 

quantity now made is increasing annually, largely be- 
cause of the improved methods used in the manufacture 
of coke, which permit the saving of the ammonia. 
Its chief advantages are that it is very concentrated, 
therefore reducing the cost of handling; it is always in 
the same form, a distinct and definite product, thus render- 
ing its purchase a safe proceeding; and it is very quick 
to act, thus making it a very useful form, especially for 
quick-growing crops. Its physical character is such as to 
permit its ready distribution in a mixture. On the other 
hand, it should not be mixed with an alkaline material, 
in which case the ammonia is liberated. Such substances 
are wood-ashes, basic-slag, potassium carbonate and slaked 
or burned lime. 

Calcium cyanamid is not an ammonia compound, but 
it is thought wise to consider it here because it is believed 
that it undergoes a gradual change when brought in 
contact with soil moisture and forms ammonia. It is a 
comparatively new product made possible by the develop- 
ments in the world of electricity. This material, some- 
times called lime-nitrogen, is now being manufactured, 
by two plants in this country. In its manufacture 
finely divided calcium carbide is placed in a heated 
retort, into which nitrogen, obtained by liquefaction of 
air and distillation, is passed. The resultant material 
is removed in the form of a hard cake which is finely 
ground, and after thorough aeration is ready for distribu- 
tion. When calcium cyanamid is free of impurities 
it contains 35 per cent of nitrogen, but the commercial 
product seldom exceeds 15 per cent. While its avail- 
ability ranks with other ammonium salts it has the 
disadvantage of causing injury to young plants unless 
it is distributed in the soil some time before planting. 



50 Fertilizers 

Differing from sulfate of ammonia it tends to sweeten 
soils rather than cause a more acid condition. 

If calcium cyanamid is used to supply a part of the 
nitrogen in a complete fertilizer, the analysis will be 
somewhat misleading. In the chemical analysis, the 
form in which the nitrogen derived from cyanamid would 
be reported would depend upon the amounts and forms 
of nitrogen derived from other sources used in the mix- 
ture. If nitrate of soda is used in the mixture, the amount 
of nitrate nitrogen reported will be greater than the actual 
amount derived from nitrate of soda, a portion being 
obtained from the cyanamid. This same condition is 
true when ammonia salts are used, a part of the nitrogen 
from cyanamid would be reported as ammonia nitrogen. 
In either case the remaining portion of nitrogen from 
cyanamid would be reported as water-soluble organic 
nitrogen. 

NITRATE NITROGEN 

Neither organic nor ammonia compounds containing 
nitrogen are capable of fully meeting the demands of 
plants for this element. The first, or organic nitrogen, 
must pass through two changes, first to ammonia, and 
then to nitrate, and the ammonia must change to a 
nitrate. 

This process already referred to is known as nitrifica- 
tion. The nitrate is directly absorbed by plants, and the 
larger portion obtained by them is taken up in this form. 
Hence, from the standpoint of availability, nitrate nitrogen 
must be regarded as the most useful form. Like ammonia 
too, a pound of it is as good as any other pound, from 
whatever product it may have been derived. It is a 
relatively concentrated material; and as it is perfectly 



Nitrogenous Fertilizers 51 

soluble, it readily distributes itself everywhere in the 
soil to which it may be applied. 

Nitrate of soda. — There are a few substances found 
in nature containing nitrogen in the nitrate form. The 
most important is nitrate of soda, a chemical compound 
composed of sodium, oxygen and nitrogen. The occur- 
rence of this material is limited to the rainless districts 
of South America, mainly Chile, where the crude nitrate 
of soda salts called Caliche are found in vast quantities. 
These crude salts contain from 5 to 30 per cent of nitrate 
of soda. In the process of refining for market they are 
dissolved and recrystallized in order to remove as far as 
possible the impurities associated with them. There 
are great quantities of a lower grade containing 3 per cent 
or less of nitrate of soda which are not at present con- 
sidered sufficiently rich to refine. The chemically pure 
salt, nitrate of soda, contains 16.47 per cent of nitrogen, 
and the commercial article, called "Chili saltpeter," 
contains from 15.5 to 16 per cent. The impurities which 
remain in it consist mainly of sodium chlorid, or common 
salt, which, together with moisture, causes a lower per- 
centage in the commercial product. Because nitrogen 
in nitrate of soda is in the nitrate form and, therefore, 
soluble, it is often advanced that there is greater loss 
from leaching into the drainage waters. Experiments 
show this is untrue or at any rate the efficiency of this 
material is greater than that of any other because more 
is returned in the crop as shown in the discussion of relative 
availability of the forms of nitrogen which follows. When 
nitrate of soda is mixed with other materials it has a 
tendency to cause a caking or hardening of the mixture, 
but this is no more true of nitrate of soda than of the 
potash salts. Unlike ammonium sulfate, nitrate of soda 



52 Fertilizers 

leaves in the soil an alkaline residue rather than an acid 
residue. 

The search for deposits of crude nitrate salts in other 
parts of the world has been rather fruitless, but it 
has been known for a long time that nitrate exists in 
Egypt and India in combination with potassium rather 
than sodium, which makes these deposits even more 
valuable because potassium is more valuable than sodium 
in these countries. Very recently nitrate beds have been 
reported in some parts of California, but the reports of the 
composition of the raw material have been unfavorable. 
If the most convincing theory of the formation of the 
nitrate beds is to be accepted, — namely, that gigantic 
islands of sea-grass in the ocean became isolated by 
volcanic rising of the ground, and subsequently the sea 
water evaporating they remained and decayed, — it is not 
probable that new beds are in the process of formation 
as in the case of the guanos of Peru. But there is little 
cause for alarm because experts claim the Caliche beds of 
Chile will last from 300 to 400 years before the higher 
grade salts become completely exhausted at the present 
rate of consumption. 

Calcium nitrate is a manufactured product of compara- 
tively recent origin containing its nitrogen in the nitrate 
form. It has caused much confusion because many 
names have been applied to the same material ; as, nitrate 
of lime, lime-saltpeter, basic calcium nitrate, lime-niter, 
basic nitrate, and basic lime-nitrate. It is now being 
manufactured in Norway, Austria, France and the 
United States from atmospheric nitrogen. The commer- 
cial product is a mixture of lime and calcium nitrate 
containing 12 to 14 per cent of nitrogen, though it often 
varies as much as from 9 to 14 per cent of nitrogen. 



Nitrogenous Fertilizers 53 

Potassium nitrate. — It has already been stated that 
potassium nitrate salts exist in Egypt and India. They 
are also found in Cape Colony, South Africa. The impure 
salts on the market, commonly called niter or saltpeter, 
contain 14 per cent of nitrogen and 44 per cent of potash. 
Because this material is used for manufacturing purposes, 
especially gunpowder, little is sold for fertilizer even 
though it is especially concentrated considering its con- 
tent of both nitrogen and potash. 

Ammonium nitrate is a compound now being manufac- 
tured in Norway which is superior to the other nitrogenous 
products in that it is highly concentrated and leaves no 
injurious residue in the soil. Chemically pure, it contains 
35 per cent of nitrogen, one-half in the ammonia form 
and one-half in the nitrate form. The commercial prod- 
uct, yet limited in quantity, is sold on the dry basis 
99.8 per cent pure. At the present time, the cost of 
nitrogen contained is too high to warrant the use of this 
material as a fertilizer. 



THE RELATIVE AVAILABILITY OF THE DIFFERENT FORMS 

of nitrogen. See Fig. 2, Plate 2. 

From this discussion of the kind and source of 
nitrogenous fertilizer supplies, it is shown that the form 
of the nitrogen is an important factor in determining the 
rate at which the plants may obtain it. In the case of 
nitrate, the form is such as to enable the plants to take 
it up immediately. It is, therefore, theoretically the 
best, because as soon as it comes in contact with the roots, 
it is absorbed by them ; there is no appreciable time re- 
quired to enable the element to get into a condition 
capable of ready absorption by the plant. Furthermore, 



54 Fertilizers 

its extreme solubility makes it possible, when moisture 
conditions are good, to reach every portion of the soil in 
which the roots are located, so that it is not only more 
available by virtue of its being in the right form, but 
because it readily goes to the place where the plant 
roots are. The next substance in order of availability 
is ammonia, and the rapidity with which ammonia 
will change to a nitrate makes it under many 
circumstances quite as useful. It possesses, also, one 
great advantage possessed by the nitrate, that of being 
soluble in water, and thus readily distributes itself through- 
out the surface soil. The difference in usefulness of 
these two forms seems to depend more largely upon the 
character of the season than upon the exact form. In a 
very wet season the nitrate is less useful, because liable 
to be washed below the reach of the roots, or lost alto- 
gether, and in a dry season it is more useful than the 
ammonia, because as soon as it is in solution it is capable 
of being absorbed. It must be remembered, however, 
that these two forms possess the further advantage over 
organic forms, that they are definite chemical compounds, 
which always possess the same characteristics, and under 
similar conditions they always act in the same way. If 
nitrogen is purchased as ammonia, the source of the 
nitrogen is not important ; that is, whether derived from 
the manufacture of illuminating gas, coke, or bone- 
black, or from one of the newer ammonia compounds, if 
it is ammonia, it is identical in character. The same is 
true of nitrate — the original source of the nitrogen is 
immaterial. 

The availability of nitrogen in organic forms, as already 
pointed out, depends upon the rapidity with which they 
will change to the nitrate under varying conditions. 



Nitrogenous Fertilizers 55 

Such products as dried blood, dried meat, dried fish and 
concentrated tankage change rapidly, and are, therefore, 
good forms, while products like raw leather and horn 
meal are very slow to change. 

The practical point, and the one of prime importance 
to the farmer, is, then, to know how to estimate the rela- 
tive value or usefulness of these different products, what 
is the rate of availability as compared with nitrate, and 
thus the relative advantage of purchasing the one or the 
other, at the ruling market prices. Relative values, 
however, cannot be assigned as yet, though careful studies 
of the problem have been made, chiefly by what are known 
as "vegetation tests " ; that is, tests which show the actual 
amounts of nitrogen that plants can obtain from nitrog- 
enous products of different kinds, when they are grown 
under known and controlled conditions. An enormous 
amount of work has been devoted to the comparison of 
the availabilities of the nitrogen of the different substances 
under different conditions and with different crops, and 
tables have been prepared showing the relations thus ob- 
served. The comparative availabilities are established in 
these tables by taking the yield from nitrate nitrogen at 
100, and using this as a standard for measuring the yields 
from other substances. It will be seen, therefore, that 
the actual availabilities are smaller than the comparative 
availabilities, since the return from nitrate nitrogen never 
actually reaches 100 per cent. Furthermore, while practi- 
cally all of the effect from the application of nitrate or 
ammonia nitrogen is obtained in the first season, the 
effect from manure nitrogen or other forms of organic 
nitrogen is often considerable in the second and even the 
third season — a fact which must not be overlooked in 
the study of availabilities. The following tables give 



56 



Fertilizers 



the results obtained by different workers under average 
conditions. It also shows the recovery of nitrogen from 
different forms. The values given are far from fixed, 
since changed conditions of soil, climate, crop and the 
like may modify them to a considerable extent. At 
all events, they are a fair approximation of the actual 
conditions as they exist in most soils. 

Comparative availability of different nitrogenous substances. 



Authority 


Wag- 
ner 

AND 
DORSCH 


John- 
son 


VOORHEES 


Wag- 
ner 


Aver- 
age 


Nitrate of soda . . 


100 


100 


100 


100 


100 


Sulfate of ammonia . 


90 


— 


— 


83 


86 


Cotton-seed meal . . 


— 


76 


70 


— 


73 


Dried blood . . . 


70 


77 


70 


65 


70 


Horn meal .... 


70 


72 


— 


65 


69 


Hoof meal .... 


— 


72 


65 


— 


68 


Dried fish .... 


— 


70 


65 


— ■ 


67 


Green plant substance 
Tankage .... 
Meat meal .... 


70 
60 


68 


60 
65 


65 
53 


67 
64 
59 


Bone-meal .... 


60 


— 


65 


53 


59 


Stable manure . . 


45 


— 


Variable from 


25 


35 


Wool waste . . . 


30 


— 


2 to 30 
Variable from 


25 


27 


Leather meal . . . 


20 


— 


2 to 30 


15 


17 



The author's figures in this table furnish a fair basis for 
comparing the different materials, when used for the 
same purpose or under the same conditions. If, for 
example, the increased yield of oats due to the applica- 
tion of nitrate of soda is 1000 pounds, the yield from blood 
and cotton-seed meal would be 700 pounds, the yield 



Nitrogenous Fertilizers 57 

from dried ground fish and hoof meal would be 650 pounds, 
from bone and tankage 600 pounds, and from leather, 
ground horn and wool waste, from 20 to 300 pounds. 
The foregoing discussion shows very clearly that 
organic, ammonia and nitrate nitrogen have a very 
unequal value as sources of nitrogen. Nitrate nitrogen, 
the most valuable of all three, is seldom if ever entirely 
used by the crop. Conditions determine in a large 
degree the proportion of the nitrate nitrogen secured by 
the crop, because a smaller or larger amount escapes 
beyond the reach of the plant by leaching or into the air 
by denitrification. The amount of nitrogen returned by 
the crop in the harvest is, therefore, a direct means of 
determining the relative availability of nitrogen from the 
three different forms. Investigations conducted by Paul 
Wagner, Darmstadt, Germany, and the author, Edward. 
B. Voorhees, of the New Jersey Experiment Station, agree 
very closely. Conclusions from these works show that 
there was returned in the harvest 62 parts of nitrate 
nitrogen for every hundred parts applied ; 44 parts of 
ammonia nitrogen for every hundred parts applied and 
40 parts of organic nitrogen for every hundred parts ap- 
plied as dried blood. Hence, with the returns from 
nitrate, the highest recovery regarded as 100, the relative 
availability of the nitrogen as ammonia would be 69.7 
and of nitrogen as dried blood as 64.4. These figures 
possess great practical significance to the farmer buying 
and using the nitrogen now offered on the market in 
fertilizers. 

Conditions which modify availability. 

The foregoing discussion and figures alone are, however, 
not a sufficient guide as to the kinds to buy under all 



58 Fertilizers 

conditions, since the usefulness of the different forms are 
also dependent upon such other conditions as the char- 
acter of soil, kind of crop season and the object of the 
application. 

The character of soil is an important factor. The 
mechanical composition of a soil is a dependable guide as 
to the rapidity of leaching of the soluble forms of nitrogen. 
A loose light soil permits more rapid percolation of water 
through it to the lower layers below the reach of plant- 
roots and nitrogen is more readily leached away than in 
heavier soils possessing finer particles. Furthermore, 
some soils naturally possess conditions favorable to 
nitrification, some possess similar conditions through the 
efforts of man, and still others possess conditions unfavor- 
able to nitrification. Soils sufficiently open and porous 
to permit easy cultivation and proper circulation of air 
and moisture, and well supplied with lime and organic 
matter possess those characteristics favorable to the 
spread and development of bacteria which bring about 
a more rapid change of the form of nitrogen. Again, 
the previous treatment of a soil is an important considera- 
tion. Liberal applications of manure, and the production 
and use of leguminous crops for mammal purposes tend 
to build up the content of organic nitrogen in a soil so 
that less might be used at planting time. 

The kind of crop is an important factor, since certain 
crops grow and develop quickly, while others grow for 
a comparatively long period. Some require greater 
quantities of food in a usable form and others feed more 
slowly. It is the object in some instances to produce 
succulence, in others to produce grain. The season, 
likewise, because the changes from organic forms to 
ammonia, or nitrate, only take place when the tempera- 



Nitrogenous Fertilizers 59 

ture reaches 37° F., and when in addition sufficient mois- 
ture is present. Hence, a material which might give 
excellent results when applied to a crop that grows through 
a long period in a climate where the season is very warm 
and moist, might be very unsatisfactory where the season 
is short, cold and dry. These are a few of the conditions 
which modify the rate of the decay of the same material. 
The object of the application should also be taken 
into consideration. The rate of the feeding of the plant 
with nitrogen in organic forms is measured by the rate 
of decay of the organic material containing it, while when 
nitrate is used, its feeding is direct. The result is really 
a sort of feeding of the soil in the one case, and a direct 
feeding of the plants in the other. Where the purpose 
is to get the largest proportionate increase in crop from 
the least amount applied, either the nitrate, or the am- 
monia, or the more active of the organic forms, would be 
likely to give the best returns. Whereas, if the object 
to be attained is not so much a large increased crop as it 
is increase in the future productive capacity of the soil 
in respect to this element, the slower acting materials 
will often answer the purpose quite as well as the use of 
the more active nitrate form, because in this form no 
insoluble combinations are formed, the nitrate is freely 
movable, and if the plants do not absorb it, and heavy 
rains come, the water containing the nitrate is carried 
through the soil into the drains and the nitrogen lost. 
The disadvantage of the nitrate is, then, that there is 
a greater possibility of loss from its use than from the 
use of materials which are either insoluble, or which are 
readily absorbed. Ammonia, while perfectly soluble, is 
fixed by the other substances in the soil, and is not, there- 
fore, readily leached out. If, however, heavy applications 



60 Fertilizers 

are made, the possibility of loss is increased, because of the 
rapid change of the ammonia into the nitrate form. In 
the case of organic materials, the losses from leaching 
are seldom worthy of consideration in good practice, 
since an appreciable time is required, even in the case 
of the best forms, to change all of the nitrogen into am- 
monia, and then to a nitrate ; while in the case of the 
poorer forms, still more time is necessary to cause the 
change, and losses are not liable to occur. In the making 
up of fertilizers, all of these considerations should be care- 
fully balanced. It is the practice on the part of many 
manufacturers to use a part of each of the three forms, 
so that a continuous feeding of the plant may be insured. 
Therefore, while the fact remains that fertilizers con- 
taining only the one form may not be the poorest, the 
chances are that those which contain all forms are likely 
to give more satisfactory results. 



CHAPTER IV 

PHOSPHA TES — THEIR SO URCES, COMPOSI- 
TION AND RELATIVE VALUE 

Many farmers apply the term "phosphate" to all 
manufactured fertilizers, without regard to the kind 
and character of the fertilizing constituents contained 
in them. The term "phosphate" should only be ap- 
plied to materials which contain phosphoric acid, and 
it does not necessarily imply that the phosphoric acid 
is in an available form. The term "superphosphate" 
implies that the phosphoric acid contained in the material 
is available. The phosphates constitute a class of prod- 
ucts from which superphosphates are made, and which 
are used in the manufacture of fertilizers that contain 
immediately useful or available phosphoric acid. The 
following discussion of phosphates is quoted from the 
author's "First Principles of Agriculture." 

The phosphoric acid in artificial manures is derived 
from compounds called "phosphates." In phosphates 
the phosphoric acid is united with lime, iron and alumina, 
forming phosphates of lime, iron and alumina, as the 
case may be. The phosphates of lime are better cal- 
culated for the purpose, and are, therefore, used more 
largely than any other as a source of phosphoric acid, 
in the manufacture of artificial manures. 

The phosphates available for this purpose are not, 
however, pure salts, but exist in combination either 

61 



62 Fertilizers 

with organic substances, or with minerals, or both, the 
content of phosphoric acid and its combination with 
other substances determining the usefulness of the phos- 
phate to the manure-maker. 

The phosphoric acid in these materials is soluble with 
difficulty in the soil water; and hence in their original 
condition, or in the crude raw forms, they give up this 
element in proportion as they decompose or decay in the 
soil. Those in combination with organic substances, 
either animal or vegetable, are, as a rule, more quickly 
useful as a source of phosphoric acid than those composed 
entirely of mineral constituents. 

PHOSPHATE OF LIME, OR BONE PHOSPHATE — ANIMAL 

BONE 

The bones of animals are the chief source of phos- 
phates that exist in combination with organic matter, 
and were for a long time the main source for manurial 
purposes. 

Bone consists chiefly of three classes of substances; 
viz., moisture, organic matter, containing nitrogenous 
and fatty matter, and phosphate of lime, or bone phos- 
phate — the proportion, particularly of the nitrogen 
and phosphoric acid, depending upon the kind of bone 
and the method of its treatment. 

Bone from the same kind of animal differs in com- 
position according to the age of the animal and its loca- 
tion in the body. In a general way, the younger the 
animal the softer the bone, the poorer in phosphate of 
lime and the richer in nitrogen; the older the animal, 
the richer in phosphate of lime and the poorer in nitrogen. 
The large and hard thigh bones of an ox, for instance, 



Phosphates — Their Sources 63 

differ in composition from the softer and more porous 
bones of other parts of the body. 

The phosphate of lime of the harder bones is dense 
and compact; that from the softer bone is more open 
and porous. The chief cause of variation in the com- 
position of bones used as manure, however, is due to 
the treatment they receive. This is recognized by 
manufacturers and dealers, and different names of brands 
are used to indicate the method of manufacture or treat- 
ment. As applied, however, they do not always corre- 
spond to the methods of treatment. 

Raw bone. 

The term "raw bone" is properly applied to bone 
that has not suffered any loss of its original constituents 
in the processes of its manufacture, and is for this reason 
highly regarded by farmers, who believe that it is purer 
than any other form. This is true in a large measure, 
though the fact that it is raw bone is not altogether an 
advantage from the standpoint of usefulness. Raw bone 
too often contains considerable fatty matter, which 
makes it a difficult process to grind it fine, and which 
also has a tendency to retard the decay of the bone in 
the soil. A considerable amount of fat also reduces 
proportionately the percentage of the valuable constitu- 
ents, phosphoric acid and nitrogen. Good raw bone, 
free from meat and excess of fat, should contain on the 
average 22 per cent of phosphoric acid and 4 per cent of 
nitrogen. 

Fine bone. 

The trade terms "bone meal," "bone dust" and 
" fine bone " are used to indicate mechanical condition, 



64 Fertilizers 

or fineness of division, and do not refer especially to 
composition. These names should not be taken as 
indicating the fineness without personal examination, 
since frequently the products do not, in this respect, 
correspond to the name. 

Boiled and steamed bone. 

The larger portion of the bone used as manure has 
been boiled or steamed for the purpose of freeing it from 
fat and nitrogenous matter, both of which are products 
valuable for other purposes. The fat is, of course, of 
no value as a manure, and its absence is an advantage. 
The nitrogen, while useful as a manure, is extracted 
chiefly for the purpose of making glue and gelatine. 

By boiling or steaming, the bone suffers a loss of its 
original constituents, the chief result of which is to change 
the proportions of the nitrogen and phosphoric acid con- 
tained in it. Steamed or boiled bone contains more 
phosphoric acid and less nitrogen than raw bone, and 
is also more variable in composition, the relative per- 
centage of these constituents depending upon the degree 
of steaming or boiling to which the bone has been sub- 
jected. 

Bone that has been used for the purpose of making 
glue, where the chief object is to extract the nitrogenous 
matter, contains from 28 to 30 per cent of phosphoric 
acid and from If to If per cent of nitrogen. The steam- 
ing of bone, particularly when conducted at high pressure, 
also exerts a favorable effect upon the physical and 
mechanical character of the bone. It destroys its original 
structure, makes it soft and crumbly, and often reduces 
it to a finer state of division than can be readily accom- 
plished by grinding; and, since it is also free from fat, 



Phosphates — Their Sources 65 

and is finer, it is more directly useful as a source of phos- 
phoric acid to plants than purer raw bone. 

In some cases, the fat is extracted from bone by means 
of such solvents as petroleum or benzine. These methods 
of extracting the fat have the advantage of increasing 
the relative proportion of the nitrogen, this element 
not being attacked by the solvents. The more complete 
extraction of the fat and moisture by these methods also 
aids in the final preparation of the bone by grinding. 
Bone prepared in this way frequently contains as high 
as 6 per cent of nitrogen and 20 per cent of phosphoric 
acid. 

The nature and composition of animal bone is such 
as to make it a valuable source of phosphoric acid ; and, 
while it is largely used with nitrogenous and potassic 
materials in the manufacture of artificial manures, its 
best use is, perhaps, in the fine ground form, particularly 
for soil improvement and for slow-growing crops. 

Phosphoric acid applied in this form gradually gives 
up nitrogen and phosphoric acid to the plant; and its 
physical and chemical characteristics are such that it 
forms in the soil, during the growing season, no com- 
pounds more insoluble than the bone itself. 

Commercial grades of bone. 

Because bone and tankage are variable, a guarantee 
should be required. The market has recognized this as 
fair, and to-day bone is sold and known more by its guaran- 
tee rather than by its source. There are a number of 
grades sold under guarantee of ammonia and bone phos- 
phate of lime instead of nitrogen and phosphoric acid. 
The quantities of the different grades are becoming less 
each year, and there is often some variation in the materials 



66 Fertilizers 

offered on the market. Bone of the following analyses 
can usually be secured : 





Grades op Bone 




Percentage 
Ammonia 


Percentage 
Bone Phosphate of Lime 


Percentage 
Nitrogen 


Percentage _ 
Phosphoric Acid 


u 

3 

4 to 4.5 
2 


and 60 equivalent to 
and 50 equivalent to 
and 45 equivalent to 
and 30 equivalent to 


1.23 

2.47 

3.29-3.70 

1.65 


and 27.5 
and 22.9 
and 19.6 
and 13.75 



Bone tankage. 

Tankage is made from the residue remaining after 
boiling cattle heads, feet, clippings, cartilage and other 
refuse animal matter. It may be classed with boiled 
bone in reference to the quality of its phosphoric acid. 
Its agricultural value is further modified by the fineness 
of division; it is frequently substituted for bone in the 
manufacture of fertilizers, where phosphate derived from 
bone is regarded as an important constituent of the mix- 
ture or brand. 

While the market shows an increased tendency to limit 
such products, six distinct grades still exist as shown 
below : 

Grades of Bone Tankage 



Percentage 


Percentage 


Bone Phosphate of Lime Phosphoric Acid 


18 to 19.0 


equivalent to 40 


16.0 


equivalent to 35 


13.5 


equivalent to 30 


11.5 


equivalent to 25 


9.0 


equivalent to 20 


7.0 


equivalent to 15 



It will be observed that certain grades of tankage ap- 
proach the composition of bone in their content of phos- 



Phosphates — Their Sources 67 

phoric acid ; the nitrogen increases as the phosphoric 
acid decreases, as already pointed out in the discussion 
of nitrogenous materials. 

Other organic products. 

There are also other products which should not be 
disregarded in a discussion of phosphates, though because 
of their content of either nitrogen or potash they are 
primarily valued for them, rather than for the phos- 
phoric acid. A good example is the dried ground fish, 
which often contains as high as 8 per cent of phosphoric 
acid, or an equivalent of 17 to 18 per cent of bone phos- 
phate of lime. The phosphoric acid in dried fish is fre- 
quently more available than in other organic forms, 
owing to the fact that in the drying of the scrap it is 
often necessary to add sulfuric acid to prevent putre- 
faction. On the average, more than one-half of the 
total phosphoric acid in this product is in an available 
form. 

The phosphoric acid contained in other nitrogenous 
products, as cotton-seed meal and castor pomace, while 
not large, is of some importance, as it is relatively more 
available than in raw bone or in tankage. 

Bone-black, or animal charcoal. 

This material becomes an important source of phos- 
phoric acid for artificial manures, after it has served its 
chief and first purpose in clarifying sugar. In making 
bone-black, only the best bones are used ; they are cleaned 
and dried, and placed in air-tight vessels, and heated 
until all volatile matter is driven off ; the resultant prod- 
uct, which retains in part the original form of the bone, 
is then ground to a coarse powder; it then becomes a 



68 Fertilizers 

bone charcoal, consisting chiefly of carbon and phosphate 
of lime, though also containing small amounts of magnesia 
and carbonate of lime. 

Bone-black, as received from the refineries, contains 
the impurities gathered there, consisting chiefly of vege- 
table matter and moisture. It is somewhat variable in 
composition, containing from 32 to 36 per cent of phos- 
phoric acid and a small amount of nitrogen. It decays 
slowly in the soil, and is not now used to any extent 
directly as a manure. 

Bone-ash. 

Bone-ash is an excellent, though not large, source 
of phosphoric acid. It is exported in considerable quan- 
tities from South America, where the bones are burned 
and the bulk reduced, in order to facilitate transporta- 
tion. It does not contain nitrogen, and is more variable 
in composition than bone-black, though usually somewhat 
richer in phosphate of lime. Good samples contain 
from 27 to 36 per cent of phosphoric acid. 

Bones themselves, and the phosphates derived from 
bones, constitute a class differing from other phosphates 
used in making manures, in that they are derived directly 
from organic materials and, as a class, they possess char- 
acteristics, due to this fact, which render them more 
useful than those derived from purely mineral sources. 

MINERAL PHOSPHATES 

These constitute a class of products differing from those 
of immediate or recent animal origin mainly in the fact 
that they are not combined with organic matter, and are 
more dense and compact in their structure. They occur 



Phosphates — Their Sources 69 

in several different forms, and are procured from distinct 
sources. 

South Carolina rock phosphates. 

These are found both on the land and in the beds of 
rivers in the vicinity of Charleston, South Carolina, and 
are sometimes called "Charleston phosphates." The de- 
posits vary in thickness from one to twenty feet, through 
which the phosphate is distributed in the form of lumps 
or nodules, ranging in weight from an ounce to over a ton. 
These nodules are irregular, non-crystalline masses, often 
full of holes, which contain clay or other non-phosphatic 
materials. That obtained from the river is called "river 
phosphate," or "river rock"; and that from the land, 
"land phosphate," or "land rock." The two varieties 
do not differ materially in composition, particularly in 
the content of phosphoric acid. 

The rock contains from 26 to 28 per cent of phosphoric 
acid. Its uniformity, in connection with the fact that it 
contains but small percentages of compounds of iron and 
alumina, minerals which prevent its best use by the 
manufacturer, make it a highly satisfactory source of 
phosphoric acid. 

The river rock is secured by dredging; that from the 
land is largely dug. In either case it is washed to re- 
move the adhering matter, and then dried, when it is 
ready for grinding or shipment. South Carolina rock 
phosphate, when very finely ground, is called "floats." 
It is sometimes used upon the land in this form, and 
when used for certain crops, as turnips, for example, and 
on certain soils, notably those wet and heavy and rich in 
vegetable matter, very satisfactory returns are obtained. 

These deposits were first worked in 1868, though the 



70 Fertilizers 

presence of phosphate at this point was known at a much 
earlier date. 

Florida phosphates. 

The presence of phosphate in commercial quantities 
in Florida was discovered in 1888, since which time 
very great progress has been made in developing the 
deposits. The deposits occur in a number of forms, — ■ 
first, "soft phosphate," a whitish product, somewhat 
resembling clay, and largely contaminated with it; 
second, "pebble phosphate," consisting of hard pebbles, 
occurring both in river beds and upon the land, and 
mixed with other materials ; and third, " rock," or " bowl- 
der phosphate," which occurs in the form of stony masses 
or bowlders, both large and small. These three forms 
also differ widely in composition, both in reference to 
their content of phosphoric acid and in respect to the 
presence of other minerals. (See Figs. 3—5, Plates III 
and IV.) 

The soft phosphate is the poorest in phosphoric acid. 
It is easily prepared, and is largely used directly upon 
the land. It is also the most variable in composition, 
ranging from 18 to 30 per cent. The pebble rock is also 
variable in composition, though, when washed free of 
sand and clay, it is richer in phosphoric acid than the 
soft variety. Good samples contain as high as 40 per 
cent and over of phosphoric acid. The bulk of the 
"Florida phosphate" is believed to exist in the pebble 
form. 

The rock or bowlder phosphate, though apparently 
much less in amount, is more uniform in composition, 
and is much richer than either of the other forms. The 
clean, dry bowlder phosphate often contains as high as 



PLATE III. — Phosphate Mining. 




Fig. 3. — Phosphate Pit, Dunnellon, Florida. 




Fig. 4. — Mining Phosphate Rock by Means of Floating Dredge. 



Phosphates — Their Sources 71 

40 per cent phosphoric acid, far exceeding in richness 
the South Carolina rock superphosphate. 

Canadian apatite. 

This material is a crystallized rock of true mineral 
origin, and occurs associated to a greater or less extent 
with other materials. It is, therefore, not uniform in 
character, the phosphoric acid varying according to 
the amount of the other substances present. 

It is mined in the provinces of Quebec and Ontario, 
and separated into various grades at the mines. The 
mining is expensive, and the necessity for grading in 
addition makes the cost of production proportionately 
high. The highest grade of this phosphate is very pure, 
containing 40 per cent of phosphoric acid. 

Tennessee phosphate. 

The phosphate deposits in Tennessee were discov- 
ered in November, 1894, since which time they have 
been exploited and a rapid development made. This 
phosphate differs from the phosphate of South Carolina 
and Florida in that it does not exist as nodules, pebbles 
or bowlders, but in veins and pockets, and, therefore, 
does not need to be washed and dried previous to its 
treatment. While the phosphates from the various de- 
posits are not uniform in their composition, it is possible 
to secure large quantities that equal or exceed 30 to 32 
per cent of phosphoric acid, or 70 per cent or over of 
bone phosphate, and that are relatively free from dele- 
terious substances, thus making them not only a rich 
but a valuable source of supply for the manufacturers of 
superphosphates. 



72 Fertilizers 

Recent discoveries in western states. 

The development of the phosphate mines of South 
Carolina, Florida and Tennessee was so rapid that grave 
fears were entertained of complete exhaustion. The 
future prosperity of the agriculture of the United States, 
however, has been assured by recent discoveries of vast 
phosphate fields in Idaho, Wyoming and Montana. 
Estimates of the size of these deposits are much greater 
than those of the eastern United States already developed 
and the material is of a distinctly high-grade character. 

The conditions surrounding many of these deposits 
are especially favorable for the manufacture of acid 
phosphate. Copper smelters are situated not far dis- 
tant which are capable of producing enormous quantities 
of sulfuric acid as a by-product, which, as brought out 
later, is used in large quantities in its manufacture. 

Basic-slag. 

Thomas phosphate powder, phosphate slag, odorless 
phosphate, iron phosphate and basic-slag are some of 
the names given to a waste product found in the manu- 
facture of steel from phosphatic iron ores by a modification 
of the Bessemer process in which an excess of calcium 
oxide (lime) is used. It is a heavy, black powder weighing 
more than any of the more common fertilizer materials, 
and is extremely fine. 

The use of basic-slag is confined largely to the coun- 
tries manufacturing steel from ores high in phosphorus. 
It is produced in large quantities in England, France 
and Germany, and in those countries is not only one of 
the cheapest sources of phosphoric acid, but is regarded 
as a very valuable product. The composition varies 



Phosphates — Their Sources 73 

with the grade of ore and the amount of lime used in the 
process of manufacturing steel. The imported product 
usually contains 15 to 19 per cent of phosphoric acid. 
Among the chief constituents, other than phosphorus, 
are a number of compounds containing calcium, mag- 
nesium, iron, manganese and silicon. In general the 
composition will range within the limits following : 



Phosphoric acid 
Calcium oxide 
Magnesium oxide 
Manganese oxido 
Iron oxide . . 
Silica .... 
Alumina . . . 



12 to 20 per cent 
35 to 50 per cent 

4 to 6 per cent 

5 to 10 per cent 
12 to 18 per cent 

4 to 8 per cent 
1 to 3 per cent 



The availability of basic-slag is dependent in large 
measure upon the fineness of division and soil conditions. 
From 80 to 90 per cent of the total phosphoric acid con- 
tained in it is guaranteed available, but experimental 
evidence shows that the phosphoric acid in basic slag is 
only a little more than one-half as quickly available as 
soluble calcium phosphate. The lime contained is un- 
doubtedly an asset. Good results have been obtained 
on low wet soils, but it is only when the material is used 
in large quantity that the effects of the lime become 
noticeable. 

Manufactured phosphates. 

There are a number of phosphatic materials manu- 
factured in one way or another from minerals bearing 
phosphorus which are mentioned more as a matter of 
interest than of practical importance. 

Artificial basic-slag meal. — Many attempts have been 
made to produce by manufacture a material similar to 



74 Fertilizers 

basic-slag. When apatite or other phosphates are fused 
with lime and silica, a product is formed which is very 
similar to basic-slag, known as artificial basic-slag meal. 

Wiborgh phosphate. — By fusing feldspar, sodium car- 
bonate and phosphorite at a very high temperature, a 
product is obtained which contains from 20 to 30 per 
cent of available phosphoric acid. It has been found to 
compare very favorably with superphosphates and basic- 
slag, especially when used upon muck and peat soils. 
The cost of manufacture is too great to make this material 
of practical importance. 

Wolter phosphate. — This material is manufactured by 
fusing powdered phosphorite, sodium sulfate, calcium 
carbonate, sand and coke. When the material is hot 
it is run into water and finely pulverized after cooling. 
It compares favorably with basic-slag. 

Palmaer phosphate. — This is a high-grade phosphatic 
material containing 35 to 40 per cent of phosphoric acid 
in the reverted form, practically all of which is available. 
It is of especial importance because it affords a means 
of utilizing mineral apatite. In the process of manu- 
facture apatite is treated with chloric or perchloric acid 
generated by electricity from sodium salts. It is more 
effective than basic-slag and compares favorably with 
superphosphates. 

Phosphatic guanos. 

Guanos rich in phosphoric acid were for many years 
previous to the development of the phosphate mines 
used extensively in this country. The Peruvian guano 
of earlier times was particularly rich in nitrogen; the 
purely phosphatic guanos are rich in phosphoric acid, 
and are excellent materials. Very little of this material 



Phosphates — Their Sources 75 

reaches our markets to-day, but an occasional shipment 
is brought in from the West Indies or islands of the Pacific 
Ocean. 



PHOSPHATES AS SOURCES OP PHOSPHORIC ACID TO 
PLANTS 

The phosphates mentioned constitute what are called 
" raw materials," and, with the exception of bone, are 
not largely used directly, or without further treatment 
to render the phosphoric acid more soluble, and thus 
more immediately available to plants. As already stated, 
the phosphoric acid in them becomes food in proportion 
to the rapidity of decay, which is influenced both by the 
character of the material and the fineness of its division. 
Fine materials, too, permit of a more even distribution, 
thus bringing more particles of phosphate in contact 
with the roots of plants. 

As already stated, a phosphate is a substance in which 
the phosphoric acid is combined with lime, iron or alumina. 
The phosphates of lime are the only ones that are used 
to any extent in the manufacture of artificial fertilizers. 
The phosphoric acid contained in animal bone is in the 
form of phosphate of lime, hence the term "bone phos- 
phate of lime" has been applied to all phosphates that 
contain their phosphoric acid as phosphate of lime. In 
fact, statements of analysis of iron and alumina phos- 
phates are frequently expressed in terms of phosphate 
of lime. That is, the content of phosphoric acid is stated 
as equivalent to a certain percentage of bone phosphate, 
the term expressing the total amount of combined phos- 
phoric acid ; as, for example, a bone which contains 20 
per cent of phosphoric acid, which is the average content 



76 Fertilizers 

in good bone, is equivalent to 43.60 per cent of phosphate 
of lime. 

All phosphates are insoluble in water, but, as phos- 
phates, they are not capable of feeding the plant directly ; 
they must first decay. Hence, the usefulness of a phos- 
phate depends upon the rate of decay, or time required 
to change to such a form as to become available to the 
plant. The rapidity with which a phosphate will feed 
the plant depends upon a number of conditions, chief 
among which are, first, the character of the substance 
itself ; second, the fineness of its division ; third, the 
character of the soil to which it is applied ; and fourth, 
the kind of crop for which it is used. 

The influence of source of phosphate upon availability. 

The chief point to be observed in the first case is 
whether the substance is animal or vegetable, or whether 
it is mineral. Phosphates of immediate animal or vege- 
table origin decay more rapidly than purely mineral 
phosphates, because of the greater tendency of the organic 
matter with which the phosphate is associated to respond 
to the action of the natural agencies which cause decay. 
A bone, for example, if kept in a suitable condition of 
moisture and warmth, will soon begin to rot, the rotting 
affecting not only the animal matter, but more or less the 
phosphatic matter with which it is so closely identified, 
the fermentation primarily attacking the organic sub- 
stances, but exercising a greater or less solvent effect 
upon the phosphates. 

In the case of the mineral substances, the rate of decay 
is usually much slower, because there is no organic fer- 
mentation. The material changes or is broken up only 
by virtue of the action of the natural solvents, air and 



Phosphates — Their Sources 77 

water, and solvent substances in the soil. Furthermore, 
the phosphate of the animal bone is always a phosphate 
of lime, which, while not soluble, is in itself more readily 
attacked by the natural agencies than a mineral phos- 
phate which has associated with the bone phosphate 
other minerals that are not readily attacked by those 
agencies. That is, the mineral phosphates, while they 
are made up chiefly of phosphate of lime, are associated 
with other minerals, as iron and alumina, that are more 
slowly attacked than the phosphate of lime itself, and to 
some extent, too, prevent the full effect of the solvents, 
rather than encourage their action, as is the case with 
bone. 

Influence of fineness of division. 

In the second place, fineness of division has an im- 
portant bearing upon availability, since the finer the 
substance is ground, the greater will be the surface area 
exposed to the natural agencies which cause decay. 
Thus the application of a coarsely ground phosphate 
may not show any results the first season, while the same 
substance ground to a powder may have a good effect 
the first season ; that is, its fineness permits of the solu- 
bility of a considerable portion of its phosphoric acid. 

The character of soil as a factor influencing availability. 

In the third place, the kind of soil to which the phos- 
phate is applied may influence the rate at which the 
plants may obtain it. A soil which is open and porous, 
and thus permits the free access of air and circulation of 
water, and one which contains a large portion of other 
matter capable of decay, vegetable or animal, presents 
more favorable conditions for the solubility of phosphates 



78 Fertilizers 

than one which is close and compact in texture and purely 
mineral in its character, thus preventing the free access 
of air and water, and in which no organic changes are 
taking place. In the one case the conditions are such 
as to favor the action of the natural agencies, and in the 
other they are such as to retard their action. 

Influence of the kind of crop. 

In the fourth place, the value or usefulness of phos- 
phates is measured to some extent by the characteristics 
of the plant or crop to which they are applied. Plants 
differ in their power of acquiring food. Certain plants 
are able, because of their peculiar root system, or period 
of growth, to appropriate food more readily from in- 
soluble sources than others. 

General considerations. 

All these considerations must be observed in determin- 
ing the usefulness of a phosphate. It is believed by 
experienced farmers, though not absolutely confirmed 
by experimental inquiry, that animal bone, for example, 
is far superior, as a source of phosphoric acid, for most 
crops, to the mineral phosphates, though both may be 
ground to the same degree of fineness ; and also, that the 
finer the bone is ground, the more rapidly will it give up 
its phosphoric acid. 

Laboratory tests show that the phosphoric acid in 
bone, while insoluble in water, may be partly dissolved 
at a certain temperature by a neutral solution of am- 
monium citrate. This medium is used to determine 
what is called "available" in other phosphatic products. 
The rate of solubility in this medium is measured by 
the method of preparation of the bone and its fineness, 



Phosphates — Their Sources 79 

the phosphate in raw bone meal of the same fineness 
showing rather a lower rate of solubility than the phos- 
phates in steamed bone. The phosphate in the finest 
steamed bone is much more soluble than that in the 
coarser grades. This measure of the rate of solubility 
of bone, while not, perhaps, showing the exact rate at 
which the plants may obtain it, is a fairly safe guide in 
its use for most crops, as compared with those mineral 
phosphates which are not perceptibly soluble in this 
medium. The range of solubility of different kinds and 
grades of bone is from 20 to 75 per cent, and the average 
of a large number show about 30 per cent soluble in 
citrate of ammonia, which would be called "available" 
if found in mixed fertilizers, and probably can be as safely 
depended upon as the available shown in other products. 

In any case, animal bone, or finely ground mineral 
phosphates, cannot be depended upon to meet fully the 
needs of quick-growing crops for phosphoric acid, but 
may answer an excellent purpose where the object is 
to improve gradually the soil in its content of this con- 
stituent, as well as to supply such crops as are continuous, 
or that grow through long periods, as, for example, 
meadows, pastures and orchard and vineyard crops. 

As to the specific substance, the iron phosphate, or 
Thomas phosphate powder, experiments in Europe have 
shown that it possesses a higher rate of availability than 
other phosphates which are insoluble in water, but which 
show the same rate of solubility in ammonium citrate, 
though its solubility, or availability, is measured to some 
extent by the degree of fineness to which it is ground; 
and it is believed that its special form, the tetra-calcic, 
also exercises a considerable influence upon the rate of 
availability. 



80 Fertilizers 

European vegetation and field experiments show pretty 
clearly that two parts of phosphoric acid from the Thomas 
phosphate powder are approximately equivalent to one 
part from soluble phosphoric acid, and that this phosphate 
is especially useful on wet, marshy soils and those poor in 
lime. Experiments conducted in this country practically 
confirm these conclusions. 

The relative availability of the phosphates in the 
natural guanos has also been shown to be somewhat 
higher than in other insoluble phosphates. These latter 
substances for this reason possess a distinct value over 
others for certain classes of crops, as, for example, cran- 
berries, where the soluble phosphates would be liable to 
be washed out, and where the organic phosphates would 
be liable to float on the surface of the water, and also 
where lands are cold and sour, and not readily fermentable. 

The practical point, however, to the farmer is the 
amount of increase that he may obtain from a certain 
definite expenditure, a matter which will be discussed 
later, in the discussion of the use of fertilizers for the 
various crops. 



CHAPTER V 
SUPERPHOSPHA TES — POTASH 

The different phosphates mentioned in the previous 
chapter constitute the sources of supply for the manufac- 
ture of commercial fertilizers. That is, with the exception 
of animal bone, Thomas phosphate powder and natural 
guanos, they are used more extensively for this purpose 
than directly on the land in their raw state. They are the 
raw materials from which the manufactured phosphatic 
fertilizers are derived. The purpose of the manufacture 
is to convert them into a form in which the phosphoric 
acid is immediately available, and thus directly useful 
to the plant. The term "available" in this case is used 
in the same sense as in the discussion of the forms 
of nitrogen (Chapter III), and it means that when 
the phosphoric acid is in this form, the plants may 
acquire it immediately. 

INSOLUBLE PHOSPHORIC ACID 

Phosphate of lime is, chemically speaking, a salt capable 
of existing in various forms, the form measuring in large 
degree the rate of availability. The phosphate of lime, 
as it exists in the animal bone and mineral phosphates, 
for example, consists of three parts of lime and one of 
phosphoric acid. This is the insoluble form. It is not 
immediately available, and because of the three parts of 
g 81 



82 Fertilizers 

lime to one of phosphoric acid, which it contains, it is also 
called tricalcic, tribasic or bone phosphate, and is graph- 
ically expressed in this formula : 

Lime 

Lime Phosphoric Acid 

Lime 

That is, in each molecule, however small, there are three 
parts of lime and one part of phosphoric acid. 

SOLUBLE PHOSPHORIC ACID 

In another form, the phosphate consists of one part of 
lime and one of phosphoric acid, two parts of the lime in 
the tricalcic form being replaced with water. This form 
is called monobasic, or monocalcic. It is a saturated 
phosphate. There could be no less than one part of lime 
to one of phosphoric acid, and such phosphates are called 
acid phosphates, or superphosphates. The combination 
of the lime and phosphoric acid may be shown as follows : 

Lime 

Water Phosphoric Aeid 

Water 

This form is completely soluble in water and immedi- 
ately available, and when applied to the soil readily distrib- 
utes itself everywhere, thus making it more useful than 
any other form. 

REVERTED PHOSPHORIC ACID 

Another form of phosphate consists of two parts of lime 
and one part of phosphoric acid, and is called dicalcic, 



Superphosphates — Potash 83 

dibasic or reverted. One part of the lime in the insoluble 
is replaced by an equivalent of water, and is expressed as 
follows : 

Lime 

Lime Phosphoric Acid 

Water 

The reverted form, which means a going back from the 
soluble toward the insoluble form, is also insoluble in 
water, but is readily soluble to the roots of plants. 

It was formerly supposed that these three were the only 
forms in which phosphoric acid existed, but another form, 
in which four parts of lime are combined with one of phos- 
phoric acid, and thus called tetrabasic, or tetracalcic, has 
been found quite recently to exist in the Thomas phosphate 
powder : 

Lime 

I imfl Phosphoric Acid 

Lime 

This form is insoluble in water, though it has been found 
to be more available than the insoluble tribasic form. 



HOW SUPERPHOSPHATES ARE MADE 

Any material which contains a high content of the tri- 
calcic or bone phosphate, 60 per cent or over, is suitable 
for the manufacture of superphosphates, provided it does 
not possess a too high content of deleterious substances. 
In the manufacture of superphosphates, the phosphate is 
first ground to a fine powder, then mixed with sulfuric acid. 
The acid dissolves the phosphate, and two parts of the 
lime which are combined with the phosphoric acid in the 
tricalcic form are first set free, and then combined with the 



84 Fertilizers 

sulfuric acid, making a superphosphate (monocalcic), and 
a sulfate of lime or gypsum. That is, in this process, two 
of the three parts of the lime combined with the phosphoric 
acid to form the insoluble phosphoric acid, are removed, 
thus leaving one part of the lime combined with the phos- 
phoric acid, making the superphosphate. A pure super- 
phosphate is, therefore, a mixture of soluble phosphate 
and of sulfate of lime or gypsum. 

The difference in the superphosphates made from the different 
materials. 

In the early use of superphosphates, the chief raw mate- 
rial was animal bone. The superiority of the bone super- 
phosphate, or dissolved bone, as it was called, over the raw 
bone was manifest at once, and the familiarity with genu- 
ine bone superphosphates thus early acquired by farmers 
was, perhaps, quite as influential as any other in creating 
a prejudice in favor of their continued use in preference to 
superphosphates derived from mineral phosphates. The 
opinion that the bone superphosphate is "the best" 
is held even at the present day, notwithstanding the equally 
satisfactory results that have been obtained from the use 
of the superphosphates from other sources. 

Soluble phosphoric acid chemically identical, from whatever 
source derived. 

Chemically speaking, the soluble phosphoric acid pro- 
duced by the action of sulfuric acid upon mineral phosphates 
is identical with the soluble phosphoric acid derived from 
animal bone, and if the soluble from each could be separated 
from the other substances with which they are associated, 
there would be no difference whatever in the results of 
their use. They are identical ; just as much so as am- 



Superphosphates — Potash 85 

monia obtained in the manufacture of bone-black from 
bones is identical with the ammonia obtained in the manu- 
facture of illuminating gas or coke. In many cases, 
doubtless, superior results have been obtained from the 
use of the animal bone superphosphate, though this has 
not been due to any inferiority of the available phosphoric 
acid in the mineral superphosphate, but rather to the 
fact that substances have been compared that are not 
strictly comparable. They are radically different. The 
one contains, in addition to its available phosphoric acid, 
the only fertilizing ingredient in the mineral superphos- 
phate, considerable nitrogen, and, moreover, it contains its 
insoluble phosphoric acid in a form that is liable to decay 
more rapidly than the insoluble in the mineral phosphate. 
Soluble phosphoric acid is a definite compound. The 
source from which it is derived does not influence this 
point, and the action of a definite quantity is also identical 
when conditions are similar. 

PHOSPHATES AND SUPERPHOSPHATES ARE NOT IDENTICAL 

The idea in the term "phosphate" should also be kept 
distinct from that conveyed by the term "superphos- 
phate." The first means, and should be applied to, any 
material containing as its chief constituent phosphoric 
acid ; the other means, and should be applied to, any 
material containing soluble phosphoric acid as its chief 
constitutent. The phosphates which have already been 
described are each capable of being converted into a 
superphosphate, as animal bone superphosphate, South 
Carolina rock superphosphate, bone-black superphosphate, 
bone-ash superphosphate, Florida rock superphosphate, 
and Tennessee rock superphosphate. These superphos- 



86 Fertilizers 

phates vary in their content of soluble phosphoric acid, 
due both to the variation in the content of the phosphoric 
acid in the phosphates used as raw materials, and to the 
excellence of the method of manufacture. In other words, 
the superphosphates, while practically identical in so far 
as the form of phosphoric acid is concerned, vary in their 
total content of soluble phosphoric acid. For example, 
superphosphates made from the animal phosphates, as 
bone-black, bone-ash and the like, are usually richer in 
soluble phosphoric acid than those made from animal bone, 
or from many of the mineral phosphates, because these 
phosphates are of such a character as to enable the manu- 
facturer to convert all the phosphoric acid present into a 
soluble form, and at the same time to secure a fine, dry 
product, that may be readily handled — an important 
consideration in making superphosphates. 

Mineral phosphates, both because of their hardness and 
of the presence of other minerals, which are attacked by 
the acid, are less easily dissolved, and require more acid in 
proportion to the phosphate present than those from 
organic sources. They are also less absorbent, preventing 
the acid from permeating the mass of the material, and 
hence it is more difficult to secure good condition when 
sufficient acid is used to dissolve the phosphate. In 
making superphosphates from these materials, less acid is 
used than is required to completely dissolve the phos- 
phates, and there is, therefore, always present in them 
more or less of the insoluble phosphoric acid. 

In the case of animal bone, too, less sulfuric acid is used 
than is required to completely dissolve the phosphoric 
acid. Otherwise, a gummy, sticky product would result, 
due largely to the organic matter in the bone. The insolu- 
ble phosphoric acid in bone, bone-black and bone-ash 



Superphosphates — Potash 87 

superphosphates is, however, of greater value than the 
insoluble in the mineral phosphates, for reasons already 
given. 

In superphosphates, also, there is nearly always present 
a greater or less amount — depending upon the material 
— of the second form of phosphoric acid, the dicalcic, 
reverted or retrograde. This form usually exists in the 
greatest amounts in those made from mineral phosphates, 
which is believed to be due either to the soluble acting 
upon the insoluble portions, or to the presence of oxide of 
iron and alumina, which combine with a portion of the 
soluble phosphoric acid. The soluble goes back to the 
less soluble dicalcic form. 

Aikman states the matter very clearly in the following 
words i 1 "A change which is apt to take place in super- 
phosphate after its manufacture is what is known as 
'reversion of the soluble phosphate.' Thus it is found 
that on keeping superphosphate for a long time the per- 
centage of soluble phosphate becomes less than it was at 
first. The rate at which this deterioration of the super- 
phosphate goes on varies in different samples. In a well- 
made article, it is practically inappreciable, whereas in 
some superphosphates, made from unsuitable materials, 
it may form a considerable percentage. The causes of this 
reversion are two-fold. For one thing, the presence of 
undecomposed phosphate of lime may cause it. This 
source of reversion, however, is very much less important 
than the other, which is the presence of iron and alumina 
in the raw material. When a soluble phosphate reverts, 
what takes place is the conversion of the monocalcic 
phosphate into the dicalcic. 

"Where reversion is due to the presence of iron and 

1 " Manures and Manuring." 



88 Fertilizers 

alumina in the raw material, the nature of the reaction is 
not well understood, and is, consequently, not so easily 
demonstrated as in the former case. Where iron is present 
in the form of pyrites, or ferrous silicate, it does not seem 
to cause reversion. It is only when it is present in the 
form of oxide (and in most raw phosphatic materials it is 
generally in this form) that it causes reversion in the 
phosphate." 

Aikman also discusses the value of reverted phosphates, 
showing the estimation in which they are held in England : 
"The value of reverted phosphate is a subject which has 
given rise to much dispute among chemists. That it has a 
higher value than the ordinary insoluble phosphate is now 
admitted, but in this country, in the manure trade, this is 
not as yet recognized. At first it was thought that it was 
impossible to estimate its quantity by chemical analysis. 
This difficulty, however, has been overcome, and it is 
generally admitted that the ammonium citrate process 
furnishes an accurate means of determining its amount. 
Both on the continent and in the United States reverted 
phosphate is recognized as possessing a monetary value in 
excess of that possessed by the ordinary insoluble phos- 
phates. The result is, that raw mineral phosphates con- 
taining iron and alumina to any appreciable extent are 
not used in this country, although they do find a limited 
application in America and on the continent." 

As stated by Aikman, the reverted phosphoric acid due 
to the presence of undecomposed phosphate, as well as 
the reverted due to the presence of iron and alumina, are 
recognized by the chemists in this country, and this 
recognition is strongly encouraged by commercial interests, 
because of the fact that our mineral phosphates contain, 
as a rule, iron and alumina, which by their action reduce 



Superphosphates — Potash 89 

the percentage of the soluble. The method of chemical 
analysis which has been adopted by the American Associa- 
tion of Official Agricultural Chemists recognizes this form, 
and it is, therefore, determined and included in the "total 
available" in statements of analysis. In one state, New 
Jersey, the law requires that the dicalcic form only shall 
be recognized, and it assumes that the agricultural value 
of this form is equal to that of the soluble. 

DOUBLE SUPERPHOSPHATES 

In addition to the superphosphates made directly from 
the various materials mentioned, a special substance, 
called a "double superphosphate," which may be made by 
dissolving low-grade phosphates with an excess of dilute 
sulfuric acid, or those too poor in phosphoric acid to make 
a high-grade superphosphate. The dissolved phosphoric 
acid thus obtained, together with the excess of sulfuric 
acid, are separated from the insoluble materials by filter- 
ing, which acids, after concentration, are then used for 
dissolving the better phosphates; and because the acids 
used for dissolving the phosphates contain phosphoric 
acid, the content of available phosphoric acid in these 
products is more than double that contained in the ordinary 
products. These are mostly manufactured in Europe, and 
are not used to any extent in this country. They possess 
the advantage of containing a minimum of impurities and 
a maximum of phosphoric acid in a soluble form. 

In stating the composition of superphosphates, the three 
forms of phosphoric acid are all recognized. The sum of 
the soluble and reverted forms is called the "total avail- 
able," because these, as already stated, are regarded as 
immediately useful to the plant. In commercial trans- 



90 Fertilizers 

actions in mineral superphosphates, the total available 
only is regarded, — the content of insoluble being 
ignored. 

CHEMICAL COMPOSITION OF SUPERPHOSPHATES 

As already stated, the composition of the superphos- 
phates varies according to the richness in phosphoric acid 
of the phosphates used, and according to the character of 
the material. Bone-ash and bone-black superphosphates 
are more uniform in composition than those derived from 
the mineral phosphates, and the phosphoric acid is practi- 
cally all in the soluble form. They contain on the average 
about 16 per cent of total available phosphoric acid. The 
mineral or rock superphosphates differ from these in being 
more variable in their total content of available, and in 
showing wider variations in the proportions of reverted, 
the latter depending upon the skill in manufacture, as 
well as the character of the original material. Well-made 
South Carolina rock superphosphates contain from 12 to 
14 per cent of total available, of which 1 to 3 per cent is 
dicalcic, or reverted. There are several grades of the 
Florida rock superphosphates, due to the variation in the 
composition of the various raw phosphates. The pebble 
superphosphates are the richest, often containing as high 
as 16 or 17 per cent of total available, with varying 
percentages of reverted and insoluble. The Tennessee 
superphosphates also vary from the same cause, the richest 
showing as high as 16 to 18 per cent of total available. 
The concentrated, or double, superphosphates may contain 
as high as 45 per cent of available, practically all of which 
is soluble. The superphosphates made from animal bone 
are usually more variable in their composition than those 



Superphosphates — Potash 91 

from bone-black, bone-ash or mineral phosphates, and the 
variation is due both to the variability of the raw materials 
and the difficulties involved in their change into super- 
phosphates. The usual guarantee on an animal bone 
superphosphate is 12 per cent available, and from 3 to 5 
per cent of insoluble. These superphosphates also differ 
from the mineral superphosphates in containing nitrogen 
in addition to their phosphoric acid. They are, therefore, 
really ammoniated superphosphates. 

Well-made superphosphates contain no free acid. 

In the earlier history of the use of acid phosphates, or 
rock superphosphates, objections were urged against 
them, and are to some extent at the present time, because 
of the supposed deleterious effects of the acids contained in 
them, and these objections were undoubtedly encouraged, 
— certainly not discouraged, — by those manufacturers 
who used only genuine bone superphosphates. While the 
objections on this ground may have had some basis in 
earlier times, before their manufacture was well under- 
stood, there can be no rational objection to their use at the 
present time, when they are properly made ; for while in 
fresh superphosphates a portion of the phosphoric acid 
may be in the form of "free" phosphoric acid, this form in 
ordinary superphosphates is practically all combined with 
lime or other minerals before it is placed upon the market, 
and there is really no more "free" acid in the rock super- 
phosphate than in any other. It is quite likely this 
erroneous impression arose from the fact that strong sul- 
furic acid was used in the manufacture, and the belief 
existed that it remained as such. No free sulfuric acid 
exists in well-made superphosphates. The sulfuric acid is 
combined with the lime to form gypsum, as already de~ 



92 Fertilizers 

scribed, and the free phosphoric acid combines with the 
lime to form either a soluble or a reverted form. 

Phosphoric acid remains in the soil until taken out by plants. 

The phosphoric acid in superphosphates, though soluble 
in water, is not readily washed from the soil. The real 
object of making it soluble is to enable its better distribu- 
tion. If it were possible to as cheaply prepare the dicalcic 
or reverted form as the soluble, it would, perhaps, be quite 
as useful from the standpoint of availability. After the 
soluble is distributed in the soil, it is fixed there by com- 
bining with the lime and other minerals present. It is 
believed that it assumes, first, by the larger relative pro- 
portion of lime usually present in soils, the dicalcic form, 
though it is not positively certain that in the present of an 
abundance of lime, or that in time, it may not assume the 
insoluble tricalcic form. The soluble phosphoric acid may 
also combine with the iron and alumina in the soil, and 
form phosphates of these elements, though recent investi- 
gations lead to the conclusion that these conditions are 
much more rare than was at one time supposed. The 
time required for the fixing of the phosphoric acid, as well 
as the form it may eventually assume, depends chiefly 
upon the character and composition of the soil. In those 
rich in lime, the fixation is most rapid, though in no sense is 
the fixation immediate, and in such soils the fixation is 
probably largely completed in the course of a week. On 
clay soils, containing a low percentage of lime, and in light 
soils that contain little clay or organic matter, the fixation 
is much slower, though even in these the chances are that 
no serious loss of phosphoric acid occurs. Seldom do we 
find more than traces of phosphoric acid in drainage waters, 
even when heavy applications of soluble phosphoric acid 



Superphosphates — Potash 93 

are followed by heavy rains. The fact that the fixing 
power of soils practically prevents the loss of phosphoric 
acid should, however, not be used as an argument in favor 
of the careless use of superphosphates. 

POTASH SALTS 

Until the discovery of the mines of crude potash salts in 
Stassfurt, Germany, in 1859, and which have been worked 
since 1862, the chief source of potash for farm plants, other 
than that contained in farmyard manures, was wood-ashes. 
The supply from this source now, however, is sufficient to 
meet all immediate as well as future demands, since the 
deposits are practically inexhaustible, though notwith- 
standing the abundance of the supply and the improve- 
ments made in the methods of utilizing the various salts, 
other than potash, contained in the deposits, it is the only 
fertilizer constituent which has remained practically con- 
stant in price during the past fifteen years. In this period 
not only have wide fluctuations occurred in prices of nitro- 
gen and phosphoric acid from the different sources, but 
they are much lower now than formerly. 

The importance of potash as a constituent of fertilizers. 

It has been attested that potash is of relatively less 
importance than either nitrogen or phosphoric acid, inas- 
much as good soils are naturally richer in this element, and 
because a less amount is removed in general farming than 
of either nitrogen or phosphoric acid, as the potash is 
located to a less extent in the grain than in the straw, 
which is retained upon the farm. It is, however, a very 
necessary constituent of fertilizers, being absolutely essen- 
tial for those intended for light, sandy soils and for peaty 



94 Fertilizers 

meadow lands, as well as for certain potash-consuming 
crops, as potatoes, tobacco and roots, since these soils are 
very deficient in this element, and the plants mentioned 
require it in larger proportion than do others. In fact, 
it is believed by many careful observers — and the belief 
has been substantiated in large part by experiments 
already conducted — that the average commercial fer- 
tilizer does not contain a sufficient amount of this element. 
It is a particularly useful constituent element in the build- 
ing up of worn-out soils, because contributing materially 
to the growth of the nitrogen-gathering legumes, an 
important crop for this particular purpose. 

Forms of potash. 

Potash, as has already been stated in the discussion of 
phosphoric acid and nitrogen, exists in various forms, but 
it differs from the other elements in that its chemical form 
or combination seems to exert but relatively little influ- 
ence upon the availability of the constituent. For exam- 
ple, it may be in the form of a muriate or chlorid, of a 
sulfate or of a carbonate, and while there is a difference in 
the diffusibility of these different compounds, — that is, 
a difference in the rate at which they will distribute in the 
soil before becoming fixed, — there seems to be very little 
difference in the rate of the absorption of the potash by the 
plant. Nevertheless, the form of potash must be ob- 
served, because of the possible influence that the substances 
with which it combines may exert in reducing the market- 
able quality of the crop to which it is applied. This 
influence has been very distinctly observed, particularly in 
the growing of tobacco, sugar-beets and potatoes, and it 
has been shown that the potash in the form of a chlorid 
(or muriate) does exert a very deleterious effect, especially 



Superphosphates — Potash 95 

on tobacco. In fact, tobacco manures should not contain 
potash in the form of a muriate. For such crops as the 
various clovers, Indian corn (maize) and the various 
grasses, no particular difference has been observed, and the 
form of potash that may be procured at the lowest price 
per pound of the constituent is the one, other things being 
equal, to use for these crops. 

Kainit. 

In the next place, the potash salts that may be obtained 
are divided into two classes : first, the crude products of 
the mines, and second, the manufactured products. Of 
the crude products, kainit is the one more largely used in 
this country than any other. The potash contained in it 
is practically all in the form of muriate or chlorid. It is a 
compound of chlorid of potassium and sulfate of magne- 
sium associated with about 30 per cent of common rock 
salt or sodium chlorid. It is really a mixture varying in 
composition according to the mines from which it is ob- 
tained. It is generally sold in its natural state for ferti- 
lizer purposes, although a large part of the output of true 
kainit is used in the manufacture of sulfate of potash. The 
commercial product is guaranteed to contain 12 per cent 
of actual potash. Because of its low content of potash as 
compared with the manufactured products, the cost of 
the actual potash is usually greater than in these, owing 
to the increased cost of shipping and handling per unit of 
potash. It is more generally used near the sources of 
supply, rather than at a distance, unless the substances, as 
ordinary salt, also exert a beneficial indirect influence upon 
the soil, as is very frequently the case. It is not advisable 
to apply it immediately preceding the planting, nor in the 
hill or row, because of the danger to the young plant from 



96 Fertilizers 

the excess of both the chlorids of sodium and magnesium, 
which are injurious to the tender rootlets. Where its use 
is intended to benefit the immediate crop, it should be 
applied a considerable time before the crop is planted, in 
order that it may be well distributed, and that a portion 
of the chlorids, which are extremely soluble, may be washed 
into the lower layers, or into the drains. 

Hardsalt. 

This is another crude potash salt which is imported for 
fertilizer purposes. Its composition is very much like 
kainit except that it contains more water in combination. 
It is a mixture of chlorid of potassium, sulfate of mag- 
nesium and chlorid of sodium. The commercial product 
sold in the United States is guaranteed to contain 16 per 
cent of actual potash. Its use as a fertilizer is the same as 
that of kainit. 

Carnallit. 

Carnallit is of practical importance as a fertilizer only 
in localities not far distant from the mines and is men- 
tioned because it is the chief source of muriate of potash 
and other concentrated potash salts. It is really a double 
compound of muriate of potash and magnesium chlorid 
and has associated with it large quantities of common 
rock salt and kieserit, which is sulfate of magnesia, and 
other minerals. It contains about 9 per cent of actual 
potash and has the property of absorbing large quantities 
of water. 

Muriate of potash. 

Of the more concentrated potash salts, muriate of potash 
manufactured from carnallit is by far the most common 



Superphosphates — Potash 97 

and most generally used. It varies somewhat in composi- 
tion, according to the method of manufacture, though 
practically only three grades are met with in this country 
and only one of these is used to any great extent for agri- 
cultural purposes. These grades are : 

Basis 98 per cent pure . . contains 61.9 per cent actual potash 
Basis 95 per cent pure . . contains 60.0 per cent actual potash 
Basis 80 per cent pure . . contains 50.5 per cent actual potash 

The last grade is most common, and because it absorbs 
moisture is guaranteed to contain 48 per cent actual 
potash, though the absorption of water makes little differ- 
ence because it occurs after the material is placed in the 
bag and hence the correct amount is contained even if it 
is slightly diluted. The chief impurities of muriate of 
potash (chlorid) are common salt, or sodium chlorid, and 
insoluble matter, which are not deleterious substances. 
The lower the content of potash, the higher the content of 
impurities, though in all cases this form of potash is sold 
upon the basis of 80 per cent muriate. 

High-grade sulfate of potash. 

High-grade sulfate of potash is manufactured and used 
in much smaller quantities than muriate. It is made 
from muriate and kieserit at the present time, though 
formerly was manufactured exclusively from kainit. The 
commercial product contains from 47 to 52.7 per cent of 
actual potash, or about 90 to 96 per cent of pure sulfate of 
potash, though the most common grade contains 48 per 
cent of actual potash. It naturally varies somewhat in its 
composition, owing to impurities, either introduced or 
imperfectly removed. It is, however, regarded as prefer- 
able to the muriate for some crops, for reasons already 



98 Fertilizers 

given (page 94), in spite of its slightly greater cost. It is 
rather less diffusible than the muriate, though it is not 
inferior to it as a source of actual potash. 

Double manure salt. 

Double manure salt, or double sulfate of potash and 
magnesia, is a product obtained by refining kainit by 
recrystallization. Though it contains less potash, it is 
similar in its effects to the high-grade sulfate of potash, 
because it contains no chlorids, and is free from other dele- 
terious substances. In many cases the 25 per cent of 
sulfate of magnesium with which it is associated is believed 
to be of considerable service. The potash contained in it 
is equivalent to 25 to 26 per cent actual potash. The cost 
of potash in this material is greater than in the muriate. 

Potash manure salt. 

Potash manure salt is a term used to designate a low- 
grade muriate of potash containing 20 per cent of actual 
potash. It may be employed in a manner similar to the 
use of muriate of potash. It must be remembered, how- 
ever, that the potash contained is in the form of a chlorid, 
and that other impurities including sulfate and chlorid 
of magnesium, common salt and a few other compounds 
are associated with it. 

Double carbonate of potash and magnesia. 

This material imported from Germany is a finely divided 
powder containing about 20 per cent of potash and an 
equal amount of magnesia free from chlorids. On ac- 
count of the small amount brought to this country it is 
relatively unimportant. 



PLATE IV. — Mining and Composting. 




Fig. 5. — Mining Phosphate Rock by Hydraulic Pressure. 




Fig. 7. — Unloading and Composting New York Stable Manure 
in South Jersey. 



Superphosphates — Potash 99 

Potassium carbonate. 

Potassium carbonate is used to some extent as a fer- 
tilizer and sometimes upon compost heaps. Investiga- 
tions show that it is well adapted to tobacco-growing. It 
is a high-grade product containing 65 per cent of actual 
potash. 

Potassium nitrate. 

This material already mentioned would be especially 
valuable for agricultural purposes were it not for its 
greater value for use in the manufacture of gunpowder 
and explosives which makes it more expensive than the 
combined cost of the separate ingredients in other salts. 
It is also called nitrate of potash, niter and saltpeter, and 
contains 14 per cent of nitrogen and 44 per cent of actual 
potash. 

Feldspar and other minerals as a source of potash. 

Feldspar and a large number of other minerals including 
leucite, alunite, phonolite and nepheline have caused 
much thought and experimentation upon the part of 
chemists and investigators for a number of years as prob- 
able sources of potash. So far, little of practical impor- 
tance has been accomplished with these minerals because 
no methods have been developed which would success- 
fully extract the potash, and pulverization even to ex- 
treme fineness does not render potash contained in them 
available. 

Formations of alunite recently found at Marysvale, 
Utah, caused considerable comment at the time of their 
discovery ; but, here again, the manufacture is still in the 
experimental stage. Nor has leucite, which contains 18 
to 20 per cent of actual potash, been found practicable. 



100 Fertilizers 

Seaweeds as a source of potash. 

The flora of the Pacific Ocean includes many different 
kinds of giant seaweeds which grow luxuriantly in the 
coast waters from Alaska to Mexico. The giant kelp 
groves have attracted much attention as a source of potash. 
The ash of these weeds contains often as high as 30 per 
cent actual potash. Great possibilities are presented by 
these vast groves of seaweed because they may be har- 
vested periodically and continue productive. Up to date, 
however, no practical method has been developed which 
enables the harvest and preparations for market of this 
material at a cost sufficiently low to compete with the 
German products. 

Fixation of potash. 

Potash, like phosphoric acid, is readily fixed in the soil, 
though the chlorids with which it is combined when applied 
may form soluble compounds that are readily leached from 
the soil. For example, the chlorin combined with the 
muriate may be combined with lime or soda, forming 
soluble chlorids of lime or soda ; hence, heavy applications 
of muriate of potash may result in the exhaustion of lime 
in the soil. The fact that the potash is fixed, and that the 
chlorids remain soluble, enables the application of a large 
quantity, which might otherwise be injurious. That is, if 
muriate, of potash is applied a considerable time before the 
crop that may be injured by excess of chlorids is planted, 
the chlorids are washed out, while the potash remains. 

Another point of importance should be observed in this 
connection : the rapidity of fixation on many soils, espe- 
cially those of an alluvial character, which explains the 
recommendations frequently made to apply potash salts 



Superphosphates — Potash 101 

broadcast and immediately cultivate in, otherwise the 
fixation would take place at points of contact, and the 
distribution be incomplete. 

While it is true that potash salts readily become fixed 
in soils, it is also true that on light, sandy soils, which are 
greatly deficient in silt, clay and vegetable matter, they 
may be subject to moderate leaching and slight loss into 
the drainage water. Where irrigation is practiced on such 
soils the probability of such leaching is even greater. In 
either case caution should be exercised in their use. 



CHAPTER VI 

MISCELLANEOUS FERTILIZING MATERIALS 

In addition to the specific fertilizer materials described 
in the previous chapters, which constitute the standard 
sources of supply, a number of other products exist, and 
should be considered here. Certain of these may serve 
in the manufacture of fertilizers, and certain others, which 
are not suitable for this purpose, may be used to advantage 
either because they furnish the constituents in consider- 
able quantities, or in other ways assist in improving the 
fertility of the soil. They are often a cheap source of 
nitrogen, phosphoric acid or potash, besides contributing 
toward "condition" of soil, which exercises a decided in- 
fluence in making possible the best use of commercial 
fertilizers. 

Furthermore, while a consideration of these products 
may not be regarded as strictly pertaining to the subject 
of commercial fertilizers, a discussion of them is valuable, 
in order that certain impressions now existing concerning 
them may be corrected. These impressions, while not 
entirely erroneous, are not wholly in accord with scientific 
facts, particularly as to how far they may be substituted 
for the better products ; and on this point information as 
full and exact should be had as the limited knowledge that 
we have of the subject will permit. These various products 
cannot be strictly classified into the three main groups : 
nitrogenous, phosphatic and potassic. They are, as a rule, 

102 



Miscellaneous Fertilizing Materials 103 

rather general in their effect ; they contain small amounts 
of all the essential constituents rather than large amounts 
of one or two, and many of them are useful, because of 
their indirect action. 

Tobacco stems and stalks. 

Tobacco stems consist of the waste stems or ribs of the 
leaves, and parts of the leaves themselves, which result 
from the stripping of tobacco for the manufacture of cigars, 
or for smoking and chewing tobacco. The stalks in- 
clude the main stem and branches of the plant. The 
stems are frequently ground and sold as a fertilizer, and 
the product is valuable for its nitrogen and potash — the 
nitrogen ranging in content from 2 to 3 per cent and the 
potash from 6 to 10 per cent. They contain but small 
amounts of phosphoric acid. The nitrogen exists in 
both the nitrate and organic forms. The nitrate form 
constitutes from one-third to one-half of the total nitrogen, 
and its presence is due both to the fact that nitrogen exists 
as such in the tobacco plant, and to the fact that saltpeter 
(nitrate of potash) is frequently added in order to improve 
the marketable quality of the lower grades of tobacco. 
The potash occurs largely in the soluble form, and is free 
from chlorids. The tobacco stalks are somewhat richer 
in nitrogen than the stems, ranging from 3 to 4 per cent, 
and are poorer in potash — about 4 to 5 per cent of potash 
— though the forms of these two constituents are similar 
in the case of both to those contained in the stems. Both 
stems and stalks may be frequently obtained in the 
vicinity of towns where tobacco manufacture is carried 
on, and while more variable in their content of nitrogen 
and potash than the ground stems and stalks, due largely 
to the variations in the content of moisture, they are a 



104 Fertilizers 

useful and often a very cheap source of nitrogen and 
potash. 

These waste tobacco products are free from deleterious 
compounds, and for this reason alone are highly valued 
as a fertilizer for tobacco, as well as for small fruits, for 
which they are especially useful, because of their known 
insecticidal value. A ton of tobacco stems of good quality 
contains nitrogen equivalent to the amount contained in 
500 pounds of nitrate of soda, and potash equivalent 
to the amount contained in 200 pounds of high-grade 
sulfate of potash. They, therefore, possess a distinct 
value as a source of these constituents. 

Tobacco salts. 

Extracts of tobacco are becoming important for in- 
secticidal purposes. In the manufacture of these extracts 
there are a number of by-products produced which are 
sold for fertilizer purposes. Various names have been used 
to designate these products. The most common are to- 
bacco ammonia salt and tobacco potash salt. The former 
contains about 14 per cent of nitrogen and 6 per cent of 
potash; the latter 1 to 2 per cent of nitrogen and about 
40 per cent of potash. In localities where this industry 
is extensive, these salts are of more than ordinary interest 
because the plant-food contained in them is in highly 
available forms. The nitrogen is in the form of nitrate 
and ammonia, and the potash is the form of sulfate free 
from chlorid. 

Crude fish scrap. 

It frequently happens that farmers are so situated as 
to be able to procure directly from the fishermen the fish 
scrap from which dried ground fish is made. Very large 



Miscellaneous Fertilizing Materials 105 

amounts are used in this crude form in our coast states, 
particularly New England and the middle states. This 
material, while chiefly valuable for its nitrogen, is not uni- 
form in its content of fertilizing contituents, owing to 
the wide variation in the content of moisture, or water, 
which may range from as low as 25 to as high as 75 per 
cent. The nitrogen, of course, varies with the dry matter, 
and ranges from 2.5 to 8 per cent. The scrap also contains 
considerable amounts of phosphoric acid, ranging from 2 
to 6 per cent. The fish scrap in this form, too, is less valu- 
able as a source of nitrogen than the dried ground material, 
because of its coarser condition, requiring a longer time 
for decay. 

The whole fishes (menhaden) are also used either directly 
or in a composted form in many instances, and the ex- 
cellent results obtained are mainly due to the rapidity of 
decay of the nitrogenous substances. The economical 
purchase of these products depends largely upon the judg- 
ment of the farmer. He should be guided in determining 
their value by the amount of water contained in them. 
As they approach dryness, they become richer in the con- 
stituents of fertility. In any case, products of this sort 
should be obtained at so low a price per ton as to guarantee 
to the purchaser a maximum quantity of the fertilizing 
constituents for his money, when measured by the market 
value of the materials of known composition. 

For example, if crude fish scrap, which contains as a mini- 
mum 2.5 per cent of nitrogen, can be purchased for $5 
a ton, it will furnish nitrogen at 10 cents a pound, or at 
two-thirds the cost of this element in nitrate of soda at 
$48 a ton. Besides, the scrap contains phosphoric acid 
in good forms. At this price, the purchaser could afford 
to take the risk incident to the variability of the product. 



106 Fertilizers 

Wool and hair waste. 

Wool and hair waste have already been described in 
part, though more largely from the manufacturers ' stand- 
point, as representing materials that may be utilized in 
the manufacture of commercial fertilizers. These prod- 
ucts may frequently be obtained in large quantities and 
at a low price per ton in towns in which the original prod- 
ucts are used in manufacturing, and thus occur as wastes. 
Both are extremely variable in their composition, the wool, 
particularly, being very liable to change in this respect, 
owing both to the admixture of non-nitrogenous sub- 
stances, such as cotton, and to the source of the waste 
itself, whether it consists of the clippings and tags from the 
original fleece, or whether it is in part the manufactured 
product. Different samples show a wide range in the 
content of nitrogen and potash, from 2 to 10 per cent in 
the former, and from 1 to 3 per cent in the latter. The 
nitrogen in the waste is extremely slow in its action in the 
soil, though it may be made directly useful, both as an 
absorbent of other wastes, as in liquid manure, and as an 
ingredient of composts. Excessive quantities must be 
applied in order to obtain a marked immediate result. 

The hair waste is also variable, both on account of the 
content of moisture, as well as the admixture with it of 
other substances. 

Lime often occurs as a waste product in some industries, 
and as such it is frequently wet and pasty, and not easily 
handled. 

These wastes, when they can be purchased at a low 
price a ton, — and frequently they may be obtained as 
low as two or three dollars, — serve an excellent purpose 
as absorbents, and for use in orchards and pastures, or 
in gradually building up the fertility of poor soils. 



Miscellaneous Fertilizing Materials 107 

Sewage. 

In recent years, great progress has been made in the 
handling of sewage from cities, and there is now a product 
called "sewage sludge," which is obtained in many towns, 
as a result of its chemical treatment. Such examinations 
as have been made of this product show it to be very poor 
in the fertilizing constituents, showing less than .20 per 
cent nitrogen, .05 phosphoric acid and .05 potash. It is 
seldom worth the handling. The untreated sewage and 
garbage wastes are also obtainable in large quantities, 
and while the constituents contained in them act quickly, 
and while they are considerably richer in these than the 
sludge wastes, it seldom pays the farmer to handle them, 
owing to their offensive character and the enormous 
amount of useless moisture contained in them. 

A number of state institutions, sanatariums, prisons, 
reform schools and the like which maintain a large number 
of persons and farms run in connection with the insti- 
tution have not only installed separate sewage systems, 
but they have also equipped these systems in a manner 
which permits the use of the sewage as a part of irrigation 
systems. This practice of utilizing sewage has proved 
very successful in a number of instances, but the liquid 
should not be used as freely as water and care should be 
exercised in its application. 

Muck and peat. 

On many farms there are low, wet places, where the 
conditions are favorable for the collection of partially de- 
cayed vegetable matter. The material thus formed is 
called muck or peat. The thickness of the deposit, and 
its character, depend upon the time during which it has 
been formed, and the character of the climate. 



108 Fertilizers 

Muck is used mainly as a source of humus, and serves 
an excellent purpose as an absorbent in cattle stalls or 
yards. Fresh muck, while varying in composition accord- 
ing to its source, may be said to contain on the average 
75 per cent of water and about .75 per cent of nitrogen, 
and only traces of potash, phosphoric acid and lime. 
Air-dry muck also varies in composition, largely owing to 
the different proportions of vegetable and mineral matter 
contained in the different products, as well as the amount 
of water absorbed in its dry state. The richer it is in 
vegetable dry matter, the richer in nitrogen. The value 
of the muck as a source of humus is measured by its content 
of nitrogen, while its value as an absorbent depends upon 
its content of organic matter. It should also be re- 
membered that it is generally very acid in character. 
Analyses show its lime requirement to be as high as four 
tons calcium oxide to the acre-foot, hence its use presup- 
poses the addition of acid to the soil and the necessity for 
lime to correct this condition. The value of muck for 
either of these purposes is further modified by the labor 
necessary to secure it in a dried condition. This product 
is of doubtful value as a source of immediately available 
nitrogen. 

The usual method of securing it is to throw it out of the 
bed into heaps, and allow it to dry before it is used, either 
upon the field or in the stables. Where a muck bed exists 
upon a farm, it should first be studied in reference to its 
possible drainage. If it can be drained, it is liable to prove 
more useful where it lies than for the other purposes 
mentioned. 

At the present time, muck is air-dried, bagged and placed 
upon the market as " humus." It is very doubtful whether 
material of this character can justly be termed "humus" 



Miscellaneous Fertilizing Materials 109 

because the amount of acid contained in it is great and 
because it is in a state of slow decomposition. It is not 
uncommon to fortify it with different proportions of ferti- 
lizer materials such as nitrate of soda, acid phosphate, 
muriate of potash and the like. Whatever the process 
of manufacture, muck or humus seldom contains the 
fertility elements in sufficient quantity or proper form to 
warrant its purchase unless the price is low and compares 
favorably with the price of city manure. 

King crab, mussels and lobster shells. 

King crab is found in considerable quantities along the 
Atlantic coast, and is not only used directly as a fertilizer, 
but is also dried and ground and introduced into com- 
mercial mixtures. It is a highly nitrogenous product, 
containing in the dry state an average of 10 per cent, with 
traces only of phosphoric acid. It also possesses a high 
rate of availability, though information on this point is 
derived from the practical experience of farmers, rather 
than from actual scientific test. It is also used in many 
sections of New Jersey in its green or fresh state, either 
directly on the land or in the form of a compost, and be- 
cause of its nitrogenous character, and its tendency to 
decay rapidly, is a valuable source of this element, of 
which, in its fresh state, it contains from 2 to 2.5 per cent. 

In certain sections of the coast states farmers have 
access to an almost unlimited supply of mussels, which 
may be had for the carting. Analyses made at the New 
Jersey Experiment Station show them to contain, in their 
natural state, a very considerable amount of fertilizing 
constituents, the nitrogen reaching .90 per cent, the phos- 
phoric acid and potash .12 and .13 per cent, respectively, 
and the lime 15.84 per cent. The organic portions of the 



110 Fertilizers 

mussels decay rapidly, and serve as a fairly good source of 
nitrogen; and since this product is twice as rich in this 
constituent as average yard manure, it is well worth the 
expense of handling. 

Lobster shells are also a waste of considerable impor- 
tance, since they can be obtained at a very low cost, often 
for the carting. They contain, in their dry state, an aver- 
age of over 4 per cent of nitrogen, 3 per cent of phosphoric 
acid and about 20 per cent of lime. 

These products, of course, are not to be depended 
upon for the entire supply of constituents to crops; they 
are mainly useful in improving the natural quality of the 
soil by building it up in vegetable matter containing 
nitrogen. Their best use requires the addition of the 
minerals from other sources. 

Seaweed. 

Seaweed, already referred to in the discussion of potash 
salts, is held in high esteem in the coast states as a manurial 
product. In Connecticut, Rhode Island and New Jersey, 
the use of seaweed as a fertilizer is very general. In 
Rhode Island the annual value of the manure from this 
source has been estimated to be as high as $65,000. 

In its fresh state it contains from 70 to over 80 per cent 
of water, and is thus economically used in that condition 
only near the shore. It is frequently spread out in thin 
layers and dried, in which condition it can be profitably 
transported considerable distances. 

Seaweeds of different kinds differ in their content of 
the fertilizing constituents. Certain of them show a rela- 
tively high content of nitrogen, and others of potash, and 
they furnish more of these constituents than of phosphoric 
acid. All seaweeds contain considerable salt, though if 



Miscellaneous Fertilizing Materials 111 

they are not used in too large quantities, no serious injury 
is liable to follow. In fact, salt in some instances is a 
substance of considerable indirect manurial value. Sea- 
weed manure is certainly worthy of consideration where it 
can be obtained in quantity for the expense of carting. 

Wood-ashes and tanbark-ashes. 

Wood-ashes contain potash in one of the best forms, 
and were, in the early history of manuring, practically 
the only semi-artificial source of this element. At the 
present time, however, the supply is limited, and the aver- 
age content of potash in the commercial article is much 
lower than was formerly the case. 

The pure ash is not a uniform product. That from the 
different varieties of wood varies in composition. As a 
rule, the softer woods are poorer and the hard woods richer 
in potash than the average, the range being from 16 to 
40 per cent. 

Ashes also contain lime in large quantities, while phos- 
phoric acid is contained in much smaller quantities. 
Wood-ashes, as usually gathered for market, however, 
contain very considerable proportions of moisture, dirt, 
and the like, which cause a variability in composition 
not due to the character of the woods from which they 
are derived. The average analysis of commercial wood- 
ashes shows them to contain less than 6 per cent of potash, 
2 of phosphoric acid and 32 per cent of lime. Leached 
wood-ashes contain on the average 30 per cent of moisture, 
1.10 of potash, 1.50 of phosphoric acid and 29 per cent 
of lime and 2 to 5 per cent of magnesium oxide. 

Ashes are probably one of the best sources of potash 
that we have, so far as its form and combination are con- 
cerned, being in a very fine state of division, and in such 



1 12 Fertilizers 

a form as to be immediately available to plants. Ashes 
also have a very favorable physical effect upon soils, the 
lime present, of course, aiding in this respect. Canada 
is now the main source of wood-ashes, the substitution of 
coal for wood making the supply in this country for 
commercial purposes very limited. Owing to the vari- 
ability of this product, it should always be bought sub- 
ject to analysis, and to a definite price a pound for the 
actual constituents contained in it, which should not 
be greater than the price at which the same constituents 
could be purchased in other quickly available forms. 

Because wood-ashes have given excellent results, many 
attempts have been made to place them on the market 
and to sell similar products under the same name, and it is 
not uncommon to add to wood-ashes of low grade, fertilizer 
materials to fortify the product and to sell it as a high- 
grade material. This is especially true since the supply 
has become inadequate to meet the demand; therefore, 
great care should be exercised in its purchase. 

Tanbark-ashes are much poorer in fertilizing content than 
those obtained from the regular commercial sources of sup- 
ply. They seldom contain more than 2 per cent of potash, 
1.5 per cent of phosphoric acid and 33 per cent of lime. 

Limekiln-ashes are obtained in the burning of lime with 
wood, and are also relatively poor in potash, containing 
less than 1.5 per cent of potash and 1 per cent of phosphoric 
acid. The product is, however, much richer in lime than 
the average wood-ashes, often containing as high as 50 
per cent of calcium oxide. 

Coal-ashes. 

It is believed by many that coal-ashes, because of their 
favorable effect upon many soils, also possess considerable 



Miscellaneous Fertilizing Materials 113 

fertilizing value, whereas analyses show them to contain 
only traces of soluble potash and of phosphoric acid. The 
good results from their use is undoubtedly due to their 
beneficial indirect effect in improving the physical charac- 
ter of heavy soils. 

Cotton-hull-ashes. 

Cotton-hull-ashes were formerly made in considerable 
quantities in the southern states, where the hulls were 
used as fuel in the furnaces connected with gins and 
presses. A larger number of analyses of this product 
show it to be exceedingly variable in composition, rang- 
ing from 12 to 45 per cent of potash, 2 to 12 per cent 
of available phosphoric acid and about 10 per cent 
each of lime and magnesia. They can be safely pur- 
chased only on the basis of their actual composition. 
They are an excellent source of potash and phosphoric 
acid, because free from chlorids and other deleterious 
substances, but are not so rich in lime. They are es- 
pecially useful for such crops as are injured by the 
presence of chlorids. 

Corn-cob-ashes. 

Corn-cobs are a bulky by-product and accumulate 
rapidly at elevators and milling plants. At many of these 
plants, the cobs are burned and the ash sold for fertilizer 
purposes. Pure corn-cob-ash thoroughly burned often 
contains as high as 40 per cent soluble potash. The 
average product varies in content of potash from 6 to 
20 per cent. There is also a trace of soluble phosphoric 
acids. Because it is so variable it should be purchased 
only upon guarantee or analysis. 



1 14 Fertilizers 

Cocoa shells. 

Sometimes cocoa shells are ground and sold for fertilizer. 
They contain on the average 2.5 per cent of nitrogen, 
.75 per cent of phosphoric acid and 2.5 per cent of potash. 
They are not considered a highly valuable source of 
plant-food. 

Green sand marl. 

Marl may contain one or more of the constituents, 
phosphoric acid, potash and lime. Shell marls are usually 
very rich in lime, but contain only traces of phosphoric 
acid and potash. The green sand marls of New Jersey 
often contain very considerable amounts of phosphoric 
acid and potash, though they vary widely in composition. 
They contain, on the average, 2.20 per cent of phosphoric 
acid, 4.70 per cent of potash, and 2.90 per cent of lime. 
These constituents, particularly the potash, are, as a rule, 
slowly available. 

Marl, however, is an important amendment to soils, 
not only because of its content of mineral constituents, 
but because these constituents are associated with prod- 
ucts that exert a very favorable mechanical effect upon 
soils. Large areas of land in the state of New Jersey, 
formerly unproductive, chiefly because of physical im- 
perfections, have been made very productive mainly 
through the application of marl. 

The use of marl is now less general than when the fer- 
tilizing constituents from artificial sources were dearer, 
and when the labor of the farm was more abundant and 
cheaper. The quicker effect of more soluble fertilizer 
constituents has had an influence in reducing the use of 
marl where quick returns are desirable. Where farmers 



Miscellaneous Fertilizing Materials 115 

have deposits of marl upon their own farms, or within 
short distances of them, or can secure it at a low price, 
its application is a desirable method of improving land. 

The results from the use of marl are frequently due as 
much to the improvement of the physical condition of 
soils as to the fertility constituents added. Marl may be 
carted and spread upon the land when other work of the 
farm is not pressing, thus making it possible to get a con- 
siderable addition of fertility at a small expense. 

Agricultural salt. 

Agricultural salt which is chiefly common salt or sodium 
chlorid, is frequently used as a manure. It supplies 
no essential plant-food constituent. Its value is still 
disputed, though it is admitted that where its use is 
favorable, it is due to indirect action in aiding the decom- 
position of animal and vegetable matter, increasing the 
absorbing power of soils, and by its reaction with lime 
acting as a solvent for phosphates. Its most important 
function is in bringing the reserves of insoluble potash 
in the soil into solution. 

Upon heavy soils, the use of common salt may prove 
injurious. If carbonate of lime is present in the soil, com- 
pounds are formed which deflocculate clay and render it 
wet and sticky. 

In view of the advantages enumerated there is no good 
reason for paying from $4 to $6 a ton for this substance, 
when practically the same effect can be obtained from the 
salt contained in the crude potash salt, kainit, one-third 
of the total weight of which is common salt. This, too, 
may be had free of charge, or for the handling, as the 
market price of the kainit is based upon its content of 
potash. 



116 Fertilizers 

Powder waste. 

Powder waste also consists largely of common salt, 
though frequently containing appreciable percentages 
of nitrogen in the form of a nitrate. Its use can only be 
recommended when it can be obtained at a low price per 
ton, or for the handling, and upon soils that show a marked 
benefit from its application. 

Gas lime. 

"In gas works, quicklime is used for removing the impuri- 
ties from the gas. Gas lime, therefore, varies considerably 
in composition, and consists really of a mixture of slaked 
lime, or calcium hydrate, and carbonate of lime, together 
with sulfites and sulfides of lime. These last are injurious 
to young plant life, and gas lime should be applied long 
before the crop is planted, or at least exposed to the air 
some time before its application. The action of air con- 
verts the poisonous substances in it into non-injurious 
products. Gas lime contains on an average 40 per cent of 
calcium oxide, and usually a small percentage of nitrogen." 

Where it can be used to advantage, its cost should, as 
in the case of the other, be based on the proportion of 
actual lime present. 

Gypsum or calcium sulfate. 

Gypsum is a sulfate of lime, containing water in com- 
bination. Pure gypsum contains 32.5 per cent of lime, 
46.5 per cent of sulfuric acid and 21 per cent of water. 

Plaster of paris is prepared from gypsum by burning, 
which drives off the water it contains. 

Gypsum, like other forms of lime, furnishes directly 
the element calcium, and also exerts a favorable solvent 
effect upon the soil. It was formerly used in large quan- 



Miscellaneous Fertilizing Materials 117 

tities, particularly for clover, and it is believed that its 
favorable effect was due, not so much to the direct addition 
of lime, as to its action upon insoluble potash compounds 
in the soil, in setting free potash. Thus the application 
of plaster caused an increase in crop, because of the potash 
made available. 

We have in the eastern states two main sources of gyp- 
sum, namely, Nova Scotia and Cayuga, New York. Nova 
Scotia plaster contains on the average over 90 per cent of 
sulfate of lime, and is, therefore, purer than that obtained 
from Cayuga, which often shows as low as 65 per cent 
of pure sulfate ; the latter, however, frequently contains 
appreciable amounts of phosphoric acid. 

Phosphorus poivder. 

In many places it is possible to obtain plaster which is a 
waste in the manufacture of phosphorus. This waste 
contains the plaster in a precipitated form, and frequently 
also contains considerable amounts of phosphoric acid. 
The disadvantage of this waste lies in the fact that it is 
frequently wet and lumpy, and thus not easily handled 
and distributed. Its advantage lies in its content of 
phosphoric acid, which ranges from 1.5 to 2 per cent, 
though as a rule, it can be purchased at a lower price a 
ton than that from the regular sources. 

Calcium carbide waste. 

Calcium carbide waste is a by-product obtained in the 
manufacture of acetylene gas. It is a solid residue con- 
sisting chiefly of calcium carbonate, calcium hydrate and 
water. It is valuable as a source of lime only when it 
may be secured at an extremely low cost because it is 
usually wet or otherwise in very poor mechanical condi- 



118 Fertilizers 

tion. Unless it has been thoroughly exposed to the air, 
it contains small amounts of acetylene gas which is in- 
jurious to seeds. It should be exposed to the air before 
using or applied to the soil a few weeks before planting. 

Oxy-acetylene residue. 

Occasionally oxy-acetylene residue is to be had for 
fertilizer purposes. It is another by-product from the 
manufacture of gas, but it should not be confused with 
calcium carbide waste because its principal ingredient is 
potash rather than calcium. It contains from 45 to 55 
per cent of potash in the form of the muriate, a high per- 
centage of which is soluble in water. 

Purchase and use of miscellaneous materials. 

There are a vast number of miscellaneous fertilizing 
materials left unmentioned in the foregoing. For the 
greater part such materials are only used in localities 
where they may be secured at little or no cost outside of 
the cost of labor for hauling and distribution. In general, 
miscellaneous materials are very bulky and are not con- 
centrated in the elements of plant-food even though the 
constituents may be contained in forms valuable for plant- 
feeding purposes. In many cases the indirect effect upon 
the physical condition of the soil is quite as valuable as 
the plant-food contained, as it is the case with green sand 
marl so extensively used in New Jersey at one time. The 
same is true of peat and muck. If the material is con- 
centrated and offered for sale, it is always advisable to 
purchase only upon analysis or guarantee. This is true 
in the case of most materials which may be had at little 
cost because often they will not return the cost of carting 
and handling. 



CHAPTER VII 

FARMYARD AND GREEN-MANURES 

Of the many materials used by the farmer for soil 
improvement, there is no one so thoroughly appreciated 
as farmyard manure. It is a natural product of the farm 
and returned to the land supplies humus and small 
amounts of plant-food which assist materially in main- 
taining soil fertility. Even though the amount of plant- 
food is relatively small and poorly balanced, its use is 
faultless, almost never injurious, and the advantages are 
easily apparent. 

The advantages of farmyard manure, and green-manures 
as well, are in large measure the result of indirect action. 
They increase the water-holding capacity of soils, improve 
tilth or physical character and make the soil a more 
favorable medium for the growth and development of 
bacteria so pertinent to soil improvement. Different 
from green-manures, farmyard manure actually contains 
these bacteria. This is one of its greatest assets. 

In spite of the many advantages of manure, little care 
is given it. The losses from manure are enormous each 
year. Unfortunately proper care means considerable in- 
convenience and often an outlay of capital. When these 
losses are efficiently checked, much greater results may 
be expected. 

119 



120 Fertilizers 



Variations in manures. 

Yard manure varies in its composition according to the 
character of the animals producing it, the quality of the 
food and the object of feeding. Its composition is also 
influenced by the amount and kind of litter used, and its 
handling after it is secured. The manure from young 
animals is less valuable than that made when animals 
are full grown. Manure made from fattening animals is 
richer than that produced by dairy cows; animals fed 
upon hay and straw furnish manure much less valuable 
than when the cereal grains constitute a part of the ration. 

Manure produced by different animals. 

Horse manure is richer in nitrogen, contains less water 
and is less variable in composition than that obtained from 
cows. The manure made by animals consuming rich 
food is more liable to fermentation than that produced 
when they are fed upon bulky or watery feeds. 

Horse manure is called a "hot manure" because of its 
tendency to hot fermentation, and is for this reason par- 
ticularly useful for hotbeds, and for forcing early growth. 
Cow manure, on the other hand, is called a "cold manure," 
because less liable to fermentation. Sheep manure con- 
tains less water, and is richer in the fertilizing constituents 
than either horse or cow manure. Pig manure, while 
quite as watery as cow manure, is richer in nitrogen. 

Composition of stable manure. 

Manure from horse stables in large cities also varies 
considerably in composition. It contains on the average 
75 per cent, or 1500 pounds to the ton, of water, and 25 
per cent, or 500 pounds to the ton, of dry matter, which 



Farmyard and Green-Manures 121 

contains all of the manurial ingredients. The water is of 
no particular value ; it simply increases the cost of han- 
dling. The dry matter consists of 10 to 12 per cent of ash, 
and from 12 to 15 per cent of organic matter. The ash 
contains from 8 to 10 pounds each of phosphoric acid and 
lime, and 6 to 8 pounds of potash; while the organic 
matter contains from 8 to 10 pounds of nitrogen. 

Its indirect value, however, is often quite as great as, 
and frequently greater than, its direct value, — first, 
because of its vegetable matter, which materially improves 
the absorbing and retaining power of soils; and, second, 
because of the lower forms of life, or bacteria, contained 
in it, which induce useful fermentations in the soil. Not 
including the lime, the average ton of city manure con- 
tains but 28 pounds of actual fertilizer constituents. 

Solid and liquid portions. 

The nitrogen digested from the food, as well as a large 
part of the potash, is found in the liquid portions of the 
manure; while the nitrogen in the undigested portions, 
as well as a large part of the phosphoric acid, is contained 
in the solid residue. The nitrogen in the urine is largely 
in the form of "urea," a compound soluble in water, and 
is easily decomposed ; the potash is also soluble in water. 
These constituents are, therefore, the most active. 

Sources of loss in manures. 

Manures are susceptible to two direct sources of loss, 
the first of which is due to fermentation, which results in 
the loss of nitrogen; and the second is due to leaching, 
which may finally result in a loss of all of the constituents, 
though it is confined largely to the soluble nitrogen and 
potash. By fermentation, the nitrogen in the manure is 



122 Fertilizers 

changed to ammonia, usually in the form of a carbonate, 
which is volatile, and escapes into the atmosphere. 

Care of manures. 

Fermentation, causing loss, may be prevented by keep- 
ing the manure moist and well packed. The loss through 
leaching may be stopped if the passage of water through 
it is prevented. The best method to preserve it is to 
make it under cover, and in pits made water-tight; by 
such shelter and protection, the maximum amount of 
manurial value is obtained. The soluble constituents are 
prevented from being washed into the drain, and the loss 
of volatile compounds is reduced to a minimum. Where 
it is not practicable to have water-tight pits, manure 
should be collected in yards that drain to the center, 
plenty of absorbent used, drainage from the roof should 
not be allowed to run into the yard, and the product 
should be removed to the fields as often as possible. 

Experiments conducted to determine the extent of the 
loss of valuable constituents due to improper fermentation 
and to leaching have shown that, under average condi- 
tions of season, the loss from exposure for six months 
will range from one-third to one-half of the total constit- 
uents. This loss falls upon the most active forms; the 
constituents remaining in the manure after being sub- 
jected to such losses are the least active and directly 
useful. 

Manure preservatives. 

The loss of ammonia, both in the stables and in 
manure pits, may also be prevented by the use of land 
plaster, phosphate rock, kainit or acid phosphate, which 
have the power of fixing and retaining the volatile gases. 



Farmyard and Green-Manures 123 

A pound a day to each grown animal, sprinkled around 
in the stable, is sufficient. The same proportion and 
amount may be used on the manure heap. The value of 
this practice is, however, measured by the care of the 
manure afterward, since the fixed constituents are still 
liable to loss by leaching. 

The improvement of manures. 

Manures are improved as they are reduced in bulk, 
and as the constituents are made available or directly 
useful ; this is accomplished by well-regulated fermenta- 
tion or rotting. By well-regulated fermentation is meant 
that which results in the decay of organic matter with 
the least loss of nitrogen. The loss from fermentation is 
greatest when the manure lies in loose heaps, the access 
of air aiding the decomposition; the loss is least when 
it is packed and moist. The mixing of the manures of 
the various animals, hot and cold, also tends to reduce 
fermentation. 

If the fermentation becomes too active, great heat is 
developed, which causes the rapid escape of moisture; 
the manure is burned and has a whitish and moldy 
appearance, — it is called "fire fanged." Under these 
circumstances there is a loss of nitrogen. The "fire- 
fanging" may be prevented by keeping the heap 
moist. 

It is evident, therefore, that the improvement of 
manures, while it reduces the bulk and increases avail- 
ability of the fertilizing elements, requires care and labor. 
Whether such improvement will pay or not depends, first, 
upon the cost of labor, and second, upon the use to which 
the manure will be put. Where labor is expensive, and 
the manure is used for the growing of such gross-feeding 



124 Fertilizers 

crops as corn, the advantages derived are least. When 
the handling can be performed by the regular labor of the 
farm, and where the manure is applied to garden or quick- 
growing crops, the advantages are greatest. 

On the whole, however, it is safe to estimate that the 
least labor necessary to get the manure from the animal 
to the field is the best policy ; that is, while there may be 
loss, and while the constituents may not be so active, 
still, the financial results attained are, because of the 
saving of labor, quite as good. 

There is another advantage in the careful fermentation 
of manures which should not be overlooked, particularly 
on soils poor in vegetable matter; that is, the develop- 
ment of useful bacteria, the work of which is so important. 
What has been said of yard manure is also true for other 
manures of the farm. 

Application of yard manure. 

Two points should be kept in mind in the application 
of yard manures, — first, that they are essentially nitrog- 
enous products; and second, that they are particularly 
valuable because of the useful ferments contained in 
them. If too much is added at one time, a loss of nitro- 
gen is liable to follow, and the benefits derived from the 
ferments are limited to small areas. The manure of the 
farm should be distributed as far as possible, and supple- 
mented by more concentrated materials. Coarse manures 
are better adapted for heavy lands, while those which are 
well rotted are more useful on light soils. There should 
be as little handling of manure as possible, it should be 
carted daily when convenient, and uniformly spread, pref- 
erably on plowed ground and thoroughly worked into 
the surface soil. (See Fig. 6.) 



Farmyard and Green-Manures 



125 



Poultry and pigeon manures. 

These products accumulate in considerable amounts on 
many farms, and are often more highly valued than their 
composition warrants. Many believe that they can be 
favorably compared with high-grade commercial fertilizers. 
The good results obtained are doubtless due to the readily 




Fig. 6. — The Manure Spreader is a Labor-saving Device 
which secures an even distribution. 



available form in which the nitrogen exists, since the 
examination of these products does not show them to be 
particularly rich in nitrogen, or in the mineral elements 
of fertility, phosphoric acid and potash. 

The composition of chicken manure in the fresh state 
is very variable not only in its content of the fertility ele- 
ments but also in its content of moisture which in large 
degree determines its value for manurial purposes. The 
following table shows some of its variations : 



126 



Fertilizers 







Per Cent 




Analysis 










Water 


Nitrogen 


Phos. 
Acid 


Potash 


Fresh 










Cornell Exp. Station . . 


46.84 


1.38 


.50 


.41 


Cornell Exp. Station . . 


39.67 


.75 


.22 


.23 


New Jersey Exp. Station . 


55.00 


1.09 


.92 


.45 


N. Y. State Station . . 


59.70 


1.40 


.92 


.32 


N. Y. State Station . . 


55.30 


1.14 


.72 


.25 


Mass. Exp. Station . . 


45.73 


.79 


.47 


.18 




49.87 


.92 


.62 


.30 


Air-dried 










N. Y. State Station . . 


7.44 


1.82 


2.21 


1.11 


N. Y. State Station . . 


7.13 


1.53 


1.92 


1.01 


Mass. Exp. Station . . 


8.35 


2.13 


2.02 


.94 




7.64 


1.83 


2.05 


1.02 



Where the practice of storing chicken manure in a bin 
or discarded corn crib is common, as is so generally the 
case in small-fruit and poultry farms, it is not probable 
that the moisture is as low as in the analyses of air-dried 
manure given above. It is more likely to be in the neigh- 
borhood of 20 per cent and the percentage of the fertility 
elements is relatively less. Hence, even in the best con- 
dition, these products compare favorably with commer- 
cial fertilizers only in their content of nitrogen. Naturally 
they also vary in their composition, according to the char- 
acter of food used in their production. 

Floor sweepings from poultry houses are also valuable. 
The kind and amount of litter used is the cause of wide 
variations in the composition of such material. In general, 
it is very dry and fine, hence capable of even distribution. 

Pigeon manure differs but little from hen manure in 
composition, though usually it is much drier and some- 
what richer in nitrogen. 



Farmyard and Green-Manures 127 

These products should be cared for, since the constit- 
uents in them serve quite as well in the feeding of plants 
as those contained in the more concentrated forms, though 
a higher estimation should not be placed upon the con- 
stituents than upon those contained in commercial forms 
which are quite as good. 

It is a good practice to use phosphate rock or acid phos- 
phate with small amounts of muriate of potash or kainit 
upon the dropping boards. This serves not only as a 
preservative, but tends to make the final product a better 
balanced fertilizer mixture. 

Composts. 

In addition to the yard manure, there are about most 
farms wastes of considerable importance, weeds, grasses, 
and coarse growths of many kinds, which all contain 
greater or less amounts of manurial constituents. These 
may be utilized profitably as absorbents in the barnyard. 
When this method is adopted, the weeds should be cut 
before they have matured, or they furnish an excellent 
means of transmitting weed seeds. These waste products 
may also be used in making what are called "composts." 
These, of course, differ according to the conditions of the 
farmer. Where peat or muck is available, they are more 
advantageous than where these products are not at hand. 
The main object of the compost heap is to cause a more 
rapid decay of such products, without the loss of essential 
constituents. (See Fig. 7.) 

A good compost heap may be made by placing a layer 
of manure, then a layer of weeds or waste products of 
any kind, then a layer of lime or wood-ashes, the whole 
well moistened, and the order repeated until all of the 
products are used. The manure starts fermentation, the 



128 Fertilizers 

lime or ashes aid in the rotting, prevent acidity and keep 
the heap alkaline, and the moisture prevents too hot fer- 
mentation. By careful management destructive fermenta- 
tion is prevented, the bulk is very materially reduced and 
the quality of the constituents greatly improved. The 
chief difficulty in the making of composts, as well as with 
other methods used in the improvement of manures, is 
the expense of labor. 

It pays to take good care of, and to save, manurial 
products, to reduce wastes and to improve the quality 
of the constituents by the methods suggested. 

GREEN-MANURES 

A great deal of misconception is prevalent concerning 
the value of what are termed "green-manures." These 
do possess a distinct value, and a proper understanding 
of their place in farm management will undoubtedly re- 
sult in their large and better use, and in the consequent 
improvement of agricultural practice. By green-manures 
is meant any crop that is grown primarily for the purpose 
of improving the soil, and not for the harvested product. 

"Nitrogen gatherers" and "nitrogen consumers." 

In this sense any crop will serve as a green-manure, 
yet certain crops possess a greater value than others for 
this purpose, because they are able to obtain certain of 
their constituents from sources not accessible to all crops. 
In other words, the one class of plants can obtain the 
nitrogen necessary for their growth from the air, as well 
as from the soil ; the other, as far as we now know, can 
obtain it only from the soil. These two groups of plants 
are, therefore, classified as "nitrogen gatherers" and 
"nitrogen consumers." 



Farmyard and Green-Manures 129 

The nitrogen gatherers belong to the legume, or clover, 
family, and do not depend solely upon soil sources, but 
rather gather the element from outside, and thus do not 
reduce the content of soil nitrogen. Distinguishing 
features of the plants of this order are that the seeds are 
formed in a pod or legume, and that they have the power 
of acquiring at least a large part of their nitrogen from the 
air. These, when plowed down as green-manures, add 
directly to the crop-producing capacity of soils poor in 
nitrogen, because increasing their content of this element. 
In order that the plant may obtain its nitrogen from the 
air, however, the soil must originally contain, or must be 
inoculated with, a specific germ, the presence of which is 
manifested by the growth of nodules upon the roots, 
through which it is believed the nitrogen is obtained. 
Most well-tilled soils contain these germs in abundance. 

The "nitrogen consumers" are those which can obtain 
their nitrogen only from the soil ; these consume the nitro- 
gen existing there, and their growth and removal exhausts 
the soil of this element. 

Notwithstanding the very great advantages of the 
"nitrogen gatherers" as green-manures, they cannot be 
solely depended upon to increase the crop-producing 
capacity of the soil. That is, soils that are very poor, 
both in their content of nitrogen and of the essential 
mineral elements, cannot be made very productive by the 
sole use of green-manures. In fact, the green-manure 
crops cannot be grown with advantage unless they are 
supplied with an abundance of the mineral elements, 
phosphoric acid and potash ; hence helpful green-manuring 
for such soils must be preceded and accompanied by liberal 
fertilization with the minerals, phosphoric acid, potash 
and lime. With these added in sufficient amounts, and 



130 Fertilizers 

with the specific bacteria present in the soil, their use 
results not only in the addition of nitrogen to the soil, 
which may be useful for other plants, but by the accumu- 
lation of vegetable matter, which improves the physical 
character, usually imperfect in this class of soils. The 
nitrogen thus introduced into the soil is also in a very '■ 
good form; that is, it has a tendency to decay rapidly 
and thus supply the needs of other plants, but the helpful 
additions to the soil are limited to organic matter and 
nitrogen. The mineral constituents absorbed by the 
crop may be more available for other crops, but they 
formerly existed there. No additions of these are made 
by the growing of the crop ; hence no system of green- 
manuring can be made successful unless there is a previous 
abundance in the soil of the mineral elements, or unless 
these have been directly applied. (See Figs. 8 and 9, 
Plate V.) 

The most usejul crops. 

The crops most useful for green-manures are red clover, 
crimson clover, alfalfa, sweet clover, winter vetch, soy 
beans and cowpeas, because of their capacity to gather 
nitrogen, and because of their period and time of growth. 
Whether these plants will gather all of the nitrogen of 
their growth from the air, other conditions being good, 
depends upon whether the soil is rich or poor in nitrogen, 
since it has been shown that these plants will gather at 
least a part of the nitrogen from the soil in preference to 
that from the air, unless they are starved in respect to soil 
nitrogen. The amounts that may be gathered from the 
air, therefore, are not measured by the total content of 
nitrogen contained in the plant grown (which may, in the 
case of good crops, amount to as much as 200 pounds to 



Farmyard and Green-Manures 131 

the acre, sufficient for the use of several good crops of 
wheat, or other cereal grains), but apparently by the 
poverty of the soil in this element. The fact that an 
accumulation of nitrogen does occur has been distinctly 
shown, and their continuous growth, therefore, would 
have a tendency to over-enrich the soil in this constituent, 
unless accompanied by an abundant supply of minerals, 
particularly in the improvement of light lands and in 
orchards and vineyards, for which their right use is very 
beneficial. 

Experiments conducted in this as well as other coun- 
tries show that the nitrogen so gathered and stored in 
the soil may be readily obtained by cereal and other 
nitrogen-consuming crops. In experiments conducted by 
the New Jersey Experiment Station, on a poor, sandy 
soil, in which the mineral elements, phosphoric acid, 
potash and lime, only, were added, a crop of cowpeas 
gathered, in the roots and tops, 75 pounds of nitrogen, 
equivalent to that contained in 470 pounds of nitrate 
of soda, which when turned under was capable of feed- 
ing a rye crop with sufficient nitrogen to produce a 
most excellent crop, quite as good as that grown on 
land long under cultivation and well manured. Further 
experiments conducted with crimson clover show that 
the nitrogen gathered was capable of supplying the 
needs of fruit trees quite as well as when the nitrogen 
was applied in the immediately available form contained 
in nitrate of soda. 

If it were necessary to do so, numerous experiments 
might be cited to show that the nitrogen is gathered from 
the air by these plants, and that it is capable of providing 
that required for those other crops which can obtain it 
only from the soil. 



132 Fertilizers 

Green-manure crops that consume the nitrogen in the soil. 

In addition to the legumes, other crops are used as green- 
manures. Chief of these are rye, wheat, buckwheat, 
mustard, oats, barley and rape, not because they are 
capable of gathering nitrogen directly, but because their 
period and time of growth are such as frequently to 
enable them to serve a very useful purpose in preventing 
losses in fertility. In the growth of these crops, however, 
the only real addition to the soil is the amount of non- 
nitrogenous organic matter contained in them. The 
nitrogen gathered is in direct proportion to the amount 
contained in the soil and the relative feeding capacity of 
the plant. The nitrogen is not obtained from the atmos- 
phere, and the soil has not accumulated nitrogen by 
virtue of their growth, and is not richer in this element, 
except in so far as by their growth they prevent the 
escape of readily available nitrogen into the drainage 
waters. The nitrogen gathered is "soil nitrogen," and its 
conversion into a crop simply results in changing its form 
and place. The specific use of these crops, therefore, so 
far as directly contributing to the fertility of the soil is 
concerned, is to prevent the possible loss of nitrogen and 
other constituents by leaching, which is more liable to 
occur on uncropped soils, though they further contribute 
toward soil improvement by accumulating stores of non- 
nitrogenous vegetable matter. 

These crops, also, in order that they may produce largely, 
must be freely supplied with the mineral elements, as well 
as with nitrogen in some form, and cannot be regarded as 
a substitute for the leguminous crops, or as a substitute 
for commercial fertilizers in the permanent improvement 
of the soil, in the sense that they actually contribute to 



Farmyard and Green-Manures 133 

its content of fertility elements, — an opinion apparently 
held by many who have observed the good results that 
often follow their use. (See Fig. 10, Plate VI.) 

Mixtures are advisable. 

It is often advisable to mix legumes with non-legumes 
on the principle that a variety of seeds often make a 
better stand. This is particularly true when green- 
manures are used between cultivated crops. The mixture 
used must be made up so as to include crops which grow 
through the same period of time, crops which may be 
expected to grow when planted at the same time. For 
example, a mixture composed of sixty pounds of rye, 
twenty pounds of winter vetch and ten pounds of crim- 
son clover give most excellent results in southern New 
Jersey, whereas, conditions in northern New Jersey are 
not suitable for crimson clover. 

Precautions in the use of green-manures. 

In general, fields covered by green-manure crops should 
be plowed at the customary time regardless of the growth 
made by the plants. Legumes accumulate the greater 
proportion of their nitrogen supply in the early stages of 
growth, and it is not wise to disturb the farm system of 
labor. If too great growth is made by the crop, it should 
be mowed and harrowed before plowing. In case a heavy 
crop is plowed down, a dry season may cause a lessening 
of the moisture supply brought about by the formation 
of an impervious layer of organic matter which, also, may 
not decompose readily, resulting in serious injury to the 
physical condition of the soil. 

Non-legume crops contain, as a rule, less nitrogen, and 
besides, that contained in them is apparently less avail- 



134 Fertilizers 

able than the nitrogen contained in the green-manures 
from the leguminous crops. In their growth, too, they 
appropriate the immediately available nitrogen of the soil, 
and convert it into the less available organic form ; hence 
the crop that follows is frequently unable to obtain its 
food as readily as would have been the case, provided the 
green-manure crop had not been grown, and furthermore, 
legumes may be the cause of too much nitrogen in organic 
form, frequently experienced by potato growers. There- 
fore, while the practice of using green-manures is a desir- 
able one when properly understood, it should not be 
regarded as a means by which soils may be directly en- 
riched, except in the case of the plants of the legume 
family, where nitrogen is really added to the soil. In the 
case of all other crops, the benefit is indirect, and is in 
proportion to the amount of minerals added. 



CHAPTER VIII 

LIME AND CALCIUM COMPOUNDS 

The foregoing discussion has concerned almost entirely 
materials which actually supply the plant with needed 
food — with one or more of the essential elements of plant- 
food. Lime, though in a few instances a food, is of value 
more particularly because its indirect action is important. 
It is not only one of the oldest of all manures, but it is, 
also, the most popular and continues to increase in use. 
In spite of these facts it is still the foundation of consider- 
able misunderstanding, probably because its action is not 
restricted to any particular channel. It is known that 
by some plants it is used as a food and that its greatest 
asset is its mechanical, chemical and biological activity. 

Lime is contained in most soils in sufficient quantities 
for the support of abundant plant growth. Yet, there are 
soils, particularly light, sandy soils, to which the addition 
of lime directly promotes plant growth. Permanent 
pastures of long standing which were originally well 
supplied with lime have through years of leaching become 
deficient in this element in the surface soil, whereas the 
same soil, had it been thoroughly cultivated year after 
year, would contain sufficient lime for plant growth be- 
cause the cultivation would tend to counteract the down- 
ward movement of the lime and hold a sufficient quantity 
in the surface soil. 

135 



136 Fertilizers 

There is also a number of plants which require much 
larger quantities of lime for maximum growth than is 
naturally contained in soils. Of these plants the legumes, 
especially alfalfa, form the largest group. 

OCCURRENCE OF LIME 

It is fortunate that lime occurs in great abundance. 
Reliable estimates show that about one-sixth of the rock 
mass of the earth's crust is composed of calcium com- 
pounds. Vast tracts of country are composed of nothing 
but limestone and a large number of the more common 
minerals contain high percentages of calcium. Pure lime 
is insoluble in pure water but is readily soluble in water 
containing carbonic acid, such as rain water or soil water. 
Such waters aid greatly in the disintegration of the rock 
or mineral and carry the lime to the soil. 

In nature, lime exists chiefly as calcium carbonate or 
carbonate of lime in the forms of limestone, marble and 
chalk. It also exists in combination with magnesium 
and other chemical elements. Oyster shells and clam 
shells are composed almost entirely of calcium carbonate. 
Gypsum, a different chemical compound referred to else- 
where, also occurs in nature. 

FORMS ON THE MARKET 

Caustic lime. 

Limestone as it occurs in nature is in the form of a 
hard rock and as such it is incapable of distribution and 
likewise incapable of exerting the many functions for 
which lime is used. Limestone is really a chemical com- 
bination of calcium oxide and carbonic acid. When 



Lime and Calcium Compounds 137 

thoroughly heated, it gives up the carbonic acid, which 
goes off as a gas, leaving calcium oxide, commonly known 
as lime, and often termed "burned lime," "quick-lime," 
"stone-lime" or "lump-lime." In fact, 100 pounds of 
pure limestone when properly burned gives up 44 pounds 
of carbonic acid, leaving 56 pounds of calcium oxide. 
This material — calcium oxide — has become known as 
actual lime through the practice of farmers, manufac- 
turers and chemists who are accustomed to using it as a 
basis of comparison in estimating the quantities of lime 
in the different forms. It was the custom of farmers 
located in limestone regions to maintain kilns and do the 
burning themselves, but the increased cost of wood and 
high cost of coal for burning and scarcity of labor have 
made it practically impossible for the farmer to compete 
with the manufacturer and the home practice of burning 
has been abandoned. 

The resultant material after burning must be slaked 
before it is applied to the soil. This is done by adding 
water, which is absorbed and the lime falls to a fine powder 
ready for distribution. When chemically pure, burned 
lime contains 100 per cent of actual lime (calcium oxide), 
but the commercial product seldom contains more than 
92 per cent and varies from 78 to 96 per cent of actual 
lime, depending upon the amount of impurities in the 
limestone used for burning. 

Ground limestone. 

By the use of powerful grinding machinery used in the 
manufacture of cement, ground or pulverized limestone 
has been put upon the market. The rock limestone is 
simply ground, bagged and sold to the farmer. Chem- 
ically pure ground limestone contains 56 per cent of actual 



138 Fertilizers 

lime, though the commercial product seldom contains 
more than 52 per cent and varies from 42 to 54 per cent 
of actual lime. 

The action of this material is dependent in large meas- 
ure upon the fineness of division. Products are upon the 
market which vary from coarse pieces to a very find pow- 
der, 85 per cent of which will pass through a 200-mesh 
screen. The very coarse material acts very slowly and 
should be avoided except perhaps for use upon very light 
soils. In general, 75 per cent ground limestone should 
pass through a 100-mesh screen for profitable agricul- 
tural use. 

Calcium-magnesium lime. 

What is termed "marble lime" is made from pure lime- 
stone, and the burned lime thus obtained is practically 
pure oxide of lime. Limestone, so called, is not always 
pure. Sometimes it is a mixture of lime and magnesia, 
in which case it is the mineral "dolomite" and is termed 
"magnesian limestone." A very large quantity of the 
lime used in the eastern states is the magnesium form. 
The burned lime from the magnesian limestone contains 
from 50 to 60 per cent of calcium oxide, and 20 per cent 
or more of magnesium oxide. Similar ground products 
contain 25 to 30 per cent of calcium oxide, and 10 per 
cent or more of magnesium oxide. In some instances, 
the magnesium oxide is of value, though it is rather 
inert in its effect, and is less useful than the lime. It 
is believed to have a beneficial effect upon the bacterial 
activity of soils. A safe method in the purchase and 
use of lime is to adjust the price to the proportionate 
percentage of actual lime present, practically in the ratio 
of 10 to 7. 



Lime and Calcium Compounds 139 

Ground burned lime. 

Ground burned lime is identical to quick-lime, lump- 
lime or burned-lime except that the manufacturer grinds 
it immediately upon burning and bags it to make it ready 
for shipment. This lime requires no slaking by the 
farmer and its shipment in bags facilitates handling and 
distribution. 

Hydrated lime. 

Burned lime absorbs water freely. When water is 
added, the resultant product is calcium hydrate or 
hydrated lime. Burned lime is usually hydrated or slaked 
by the farmer before application to the soil is made, but 
recently this form of lime has become a commercial prod- 
uct. The burned lime is ground and water added in the 
form of steam which produces a very finely divided prod- 
uct. When pure and thoroughly hydrated, this material 
contains 75.7 per cent of actual lime, though the commer- 
cial product varies from 64 to 72 per cent of actual lime. 
In case the process of hydration has been incomplete, the 
percentage of actual lime may be much greater. 

Air-slaked lime. 

Quick-lime absorbs moisture, and slakes when exposed 
to the atmosphere. Lime thus slaked is called "air- 
slaked lime," and is usually less completely changed to a 
hydrate than when water is added. Quick-lime also ab- 
sorbs carbonic acid from the air, and changes back to the 
limestone form. 

Oyster shell lime. 

Oyster shells are nearly pure carbonate of lime, and 
oyster shell lime, while practically pure lime, so far as 



140 Fertilizers 

this element is concerned, is usually mixed with more or 
less dirt and other impurities, and is, therefore, not as 
rich in lime as that derived from pure limestone. When 
properly burned, it contains from 80 to 90 per cent of 
actual lime. 

Ground oyster shell lime is an excellent source of lime, 
containing from 85 to 95 per cent of calcium carbonate, 
equivalent to 48 to 53 per cent actual lime. This product 
also contains minute quantities of nitrogen and phosphoric 
acid. In some cases as much as seventy-five cents' worth 
of these elements is contained in a ton of the material. 
Ground oyster shell lime decomposes very readily in the 
soil, and the fineness of division is not such an important 
factor in determining its value as it is in the case of ground 
limestone. 

Shell marl. 

Shell marl is one of the less important sources of lime. 
There are a number of deposits in Atlantic coast states, 
but few of these are worked. This product varies much in 
its content of lime according to the amount of impurities 
laid down with it, though it often contains as high as 95 
per cent of calcium carbonate, equivalent to 53 per cent 
of actual lime. When it may be secured reasonably, it 
is one of the best forms of lime, because it is really a 
material which was at one time in solution, and hence, its 
extreme fineness of division makes its action immediate 
and complete. 

ACTION OF LIME IN SOILS 

Lime has already been referred to as a plant-food. Its 
indirect actions are numerous, producing many specific 



PLATE VI. — Wheat and Potatoes. 




Fig. 



10. — Wheat Grown as a Winter Cover-crop Preceding 
Potatoes, Freehold, New Jersey. 




Fig. 13. — Making an Application of One and One-half Tons of 
Quicklime to the Acre for Alfalfa after Potatoes. 



Lime and Calcium Compounds 141 

effects which are not limited to any one field. It affects 
the soil itself, changes its texture and mechanical proper- 
ties, such as its power of taking up and holding moisture. 
It acts upon the supply of plant-food stored in the soil and 
assists the decomposition of organic matter and mineral 
substances. Most important of all is the influence which 
lime exerts upon the microorganic life of the soil, so essen- 
tial in changing dormant to active forms of plant-food. 
Hence, the activities of lime in the soil may be said to 
be threefold, — mechanical, chemical and biological. 

Mechanical effects of lime. 

It is often stated that lime makes heavy soils lighter 
and light soils heavier. This is the apparent effect rather 
than the actual. Applications of lime upon heavy soils 
make them less sticky, more crumbly, more friable, more 
easily cultivated, and water passes through them more 
rapidly as the result of increased porosity. This condition 
is brought about by the flocculation or aggregation of the 
fine clay particles preventing shrinkage in dry weather. 

Upon light soils the reverse is true. An application of 
lime tends to increase the cohesive power of the soil, 
resulting in a greater water-holding capacity, as well as 
increasing the power to absorb moisture from below by 
capillarity. Light, sandy soils may, however, be injured 
by large applications of lime, especially if it is in the 
caustic form which causes a greater porosity and allows 
water to pass through too rapidly. Upon muck or peat 
soils, lime should always be mixed with the surface soil. 
A layer of lime spread over the surface of such soils has a 
tendency to exhaust the organic matter, and injury may 
follow especially in case of drouth because the water- 
holding capacity is decreased. 



142 Fertilizers 

Chemical effects of lime. 

Roots of peanuts exude small quantities of acid during 
growth, and likewise organic matter during decomposi- 
tion gives off acids. This is really a provision of nature 
because the acids produced in this manner aid in making 
the soil stores of mineral plant-food available, but an ac- 
cumulation of these acids which is bound to follow is 
sure to give rise to compounds poisonous and harmful to 
vegetable life. Lime has long been used to neutralize 
these so-called soil acids, and this chemical effect is un- 
doubtedly the best known of all the advantages derived 
from the use of lime. To correct acidity, or sweeten 
sour soils, is a function of lime thoroughly appreciated and 
well understood. This practice also kills many of the 
lower forms of plant life which flourish on sour soils and 
allows the more nutritive plants to grow. 

Lime supplies a necessary base. 

Soils that contain insufficient basic compounds such as 
carbonates of calcium, magnesium, potassium and sodium, 
are not in a condition to produce maximum crops. The 
absence of such compounds permits the accumulation of 
acids. Under such conditions normal decomposition of 
organic matter, the formation of nitrate nitrogen from 
ammonia, and organic matter, and the utilization of at- 
mospheric nitrogen by bacterial activity are severely 
hindered. While the correction of acidity and the addi- 
tion of lime as a basic-compound are more or less analo- 
gous, it is thought best to mention the latter to point out 
the fact that the addition of just enough lime to correct 
acidity may not be sufficient to promote chemical and 
bacteriological functions. (See Figs. 11 and 12, Plate VII.) 



Lime and Calcium Compounds 143 

Lime assists the decomposition of organic matter. 

Soils supplied with calcium carbonate or other basic- 
compounds admit the normal decomposition of organic 
matter which is the foundation of the formation of nitrate 
nitrogen under conditions permitting the proper circula- 
tion of air and moisture. Soils lacking calcium carbonate 
or other basic-compounds permit the rapid accumulation 
of free acids which poison the organisms responsible for 
decomposition. 

Lime makes soil potash available. 

Many soils contain potash in large quantities in a form 
not usable by plants. Soluble calcium compounds are of 
prime importance in the conversion of some of this soil 
potash into forms available for use by plants. The 
effect of soluble calcium compounds in making the in- 
soluble potassium compounds of the soil soluble may be 
readily seen upon heavy clay soils or heavy limestone 
soils where good crops of clover are produced annually 
without the addition of potash salts. Though all of the 
conditions influencing this change are unknown, yet it 
is safe to say that it is primarily dependent upon the 
nature of the potassium compounds existing in the soil. 

Lime makes soil phosphates available. 

Compounds containing phosphorus, especially phos- 
phates of iron and aluminum, occur in many soils. These 
particular compounds are very slowly soluble in soil water. 
The change to a more soluble form is brought about more 
readily in the presence of lime, especially when it is in the 
form of carbonate or hydrate. It was thought for a long 
time that use of lime where superphosphates are used in 



144 Fertilizers 

abundance rendered the phosphoric acid less efficient as 
a plant-food, but experiments have shown this theory to 
be greatly overdrawn. 

Less plant-food required. 

Careful study of the foregoing paragraphs shows clearly 
that less plant-food is required where lime is used in liberal 
quantity. In general, less nitrogen, phosphoric acid and 
potash need be added to soils well supplied with lime and 
in good tilth for satisfactory crop production than in the 
case of soils deficient in lime. 

Injurious chemical effects. 

Lime hastens the decomposition of organic matter and 
the formation of nitrates, as previously stated. If condi- 
tions are unfavorable to the formation of nitrates, the 
decomposition of organic matter may be accompanied by 
a loss of nitrogen which escapes into the air as a gas. In 
case all conditions are favorable for nitrification, nitrate 
nitrogen may be formed in the soil more rapidly than the 
plant-life present is capable of utilizing it and much of it 
would be leached from the soil and lost in the drainage 
water. This is more likely to occur in connection with 
the use of burned or hydrated lime, especially on light 
soils, than with the use of ground limestone. 

Effects of gypsum. 

Gypsum, land plaster or calcium sulfate previously 
mentioned should not be confused with lime, though it is 
similar in the respect that it carries the element calcium. 
Unlike lime, gypsum will not correct acidity, and its con- 
tinued use actually makes soils more acid, but it has the 
advantage of changing ammonium carbonate which is 



Lime and Calcium Compounds 145 

volatile into the stable form of ammonium sulfate. For 
this reason it is exceptionally useful as a deoderant and 
absorbent in stables. It tends to preserve the nitrogen of 
manure rather than to expel it as do burned and hydrated 
lime. 

BIOLOGICAL EFFECTS OF LIME 

Few farmers realize or appreciate the practical impor- 
tance of the biological effects of lime which are so im- 
portant in controlling the various fermentative actions 
which go in so abundantly in all soils. Lime not only 
assists the decomposition of organic matter but it furnishes 
a necessary base with which nitric acid combines in the 
process of nitrification, and it is most important in the 
formation of nitrate nitrogen. Lime creates conditions 
favorable for the growth and development of soil organisms 
which are so important in gathering and fixing nitrogen, 
and at the same time destroys many kinds of bacteria and 
fungi which are the cause of plant-diseases such as " rust," 
"smut" and "club-root." 

Biological effects may be harmful. 

Too great an application of lime, causing a strongly 
alkaline soil, may prevent the normal process of decom- 
position and nitrification. Fermentation of organic matter 
goes on when there is a certain amount of alkalinity 
present; while, on the other hand, the presence of 
acidity seems to retard and check it. Too great an 
amount of alkalinity, however, would retard fermenta- 
tion as much as too great acidity. This is true more 
particularly in case of caustic lime, but the duration of 
the injury ceases when it has been changed to the 
carbonate form. 



146 Fertilizers 

There are some plant-diseases, notably potato scab, 
which thrive far better under alkaline soil conditions, but 
in no case is the disease caused by the application of lime. 
The bacteria or fungi which cause the disease must be 
present in the soil or subsequently introduced. Lime 
merely creates conditions favorable for the spread and 
development of the disease-causing organism and for the 
development of the disease. 

It might be added that the character of native vegeta- 
tion is greatly influenced by the presence or absence of 
lime in soils just as farm crops are influenced. Chestnut 
trees, rhododendrons, arbutus, blueberry, huckleberry 
and many other wild plants prefer soils not rich in lime ; 
while, on the other hand, leguminous crops, alfalfa, clovers, 
soy beans, cow peas, beans, peas, wistaria, locust trees and 
the like, prefer soils exceptionally well supplied with lime. 
The common weed known as sheep sorrel, and many crops 
including the watermelon, strawberry and cranberry, 
thrive on soils distinctly acid. 

THE USE OF LIME 

A knowledge of the forms of lime and the action of lime 
in a soil is contingent with the efficient use of lime which 
is to a greater or less extent an individual problem with 
each farmer because soils, crops and farming systems 
vary so widely, but there are a few fundamental principles 
which should be thoroughly understood by every farmer. 
These principles involve a number of questions the most 
important of which are : do soils need lime ; how much 
lime should be used; how and when should it be 
applied; and what form of lime is best suited to exist- 
ing conditions? 



Lime and Calcium Compounds 147 

Do soils need limef 

There are a number of ways to determine whether a 
soil needs lime. It is known that lime leaches out of soils, 
that crop production and decomposition of organic matter 
increase acidity, and therefore the application of lime 
becomes necessary in the course of time. For these reasons 
the history of any field is an important guide. There is 
a common weed — sheep sorrel — which in the absence 
of cultivation and crowding thrives in acid soils, and it is 
one of the best natural indications of the need of lime. 
An attempt to raise red clover — a crop decidedly respon- 
sive to lime — is a reliable method to determine the char- 
acter of soil so far as lime is concerned if there is no serious 
lack of potash which may have a similar effect. 

There are a number of chemical tests which are very 
accurate but are not entirely satisfactory for the farmer's 
use. The litmus paper test serves its purpose in the 
laboratory, but it is not always reliable in the field. It 
is based on the fact that blue litmus paper turns red 
when placed in contact with acid, and red turns blue 
when in contact with basic compounds such as lime. 
Hence an acid soil will turn blue litmus red, and if such 
is the case, the need of lime is indicated. When a 
little finely pulverized soil fails to show any visible 
effervescence when it is covered with dilute hydrochloric 
acid, it is a good indication that the proportion of 
carbonate of lime must be below what is desirable for the 
healthy growth of vegetation, but this is not an infallible 
rule nor a positive sign that the soil contained excessive 
amounts of acid. Chemical tests of absolute depend- 
ability may be made in properly equipped laboratories, 
and it is well for farmers to obtain such tests. But the 



148 Fertilizers 

indications at the disposal of the farmer should be suf- 
ficient when good judgment is exercised. 

The application of lime. 

The character of soil, kind of crop and character of 
farming are the most important factors upon which the 
use and application of lime depend. In general, however, 
it is better to make frequent and small applications than 
large applications every five or ten years. On soils which 
are poor, light and lacking in organic matter or dry, the 
application should be small, varying from 500 to not more 
than 1200 pounds of actual lime or its equivalent to the 
acre every two or three years. On heavy soils composed 
largely of clay and well filled with organic matter, the 
application should be much heavier, from 1200 to 3000 
pounds of actual lime or its equivalent to the acre every 
two or three years. Soils of this description will make 
better use of larger quantities, and there is less danger of 
injury to soil or crop. If ground limestone is used, even 
larger amounts may be applied. 

There are certain crops which respond greatly to lime, 
others that are negative and still others that are actually 
injured when lime is present in the soil in any quantity. 
The farmer must study the particular crop he is growing 
and the effect lime has upon its development in order 
that the application of lime may be properly adjusted to 
the requirements of the crop as well as to the soil. 

When and how to apply lime. 

The time of application depends primarily upon con- 
venience, but there are a few general rules which it is 
well to follow. Lime should be applied to the surface 



Lime and Calcium Compounds 149 

after plowing and harrowed in, because it works down- 
ward and naturally leaches into the lower layers of soil. 
For best results it should be applied at a time when the 
soil is well filled with organic matter and a crop should be 
planted soon after its application to utilize the nitrate 
nitrogen which is a natural result of its action upon the 
organic matter. 

While it is often most convenient to apply lime in early 
spring, on most farms, the rotation practiced or the crop 
will in many cases fix the time of application ; for example, 
previous to seeding clover or alfalfa. In the case of caustic 
lime, applications may be made upon plowed ground in 
fall without injury to seed. When barnyard manure or 
fertilizer containing nitrogen in the ammonia or organic 
form are to be applied to the same field with caustic lime, 
the manure and fertilizer should be well incorporated with 
the soil and the lime applied after an interval of two 
weeks or more. 

The form of lime to use. 

It is possible to conceive of conditions under which a 
specific form of lime should be used to the entire exclu- 
sion of other forms ; and yet, in general, the form of lime 
to use depends primarily upon the cost of a pound of 
actual lime or calcium oxide, and the quantity used should 
be regulated by conditions of soil, kind of crop and the 
like. In other words, cost is an important factor. The 
farmer buying lime should first consider the cost of actual 
lime in the various forms at his disposal. The cost of a 
pound of actual lime is easily calculated by multiplying 
the guaranteed percentage of calcium oxide by twenty 
and dividing the price of a ton by it. The following table 
shows this calculation clearly : 



150 Fertilizers 

Comparative Cost of Actual Lime in Different Forms 



Kind or Form of Lime 


-a 

H B 
g| 

< 
P 

O 


& 




2s 

n * B 

9 z « 
b o 1 

gel 

S fc 

2 o 
<3 


re 
O fa 

o ° 

O » w 

K 

OPL, jJ 

po2 
3* 

3o 

o 


fa 

O i 
o 

,9 fa a 

Oog 

F z 

g b J 
5 o -J 
kCl, b 

£ a 

s £ 

oO 
O 


Burned lump lime 
Ground burned lime . 
Hydrated lime . . . 
Ground limestone . . 


90(X20) = 
90(X20) = 
70(X20) = 
50(X20) = 


1800 
1800 
1400 
1000 


3.50 
6.00 
6.00 
3.00 


3.50 
1800 
6.00 
1800 
6.00 
1400 
3.00 
1000 


$.0019 
.0033 
.0042 
.0030 



At the same time, the cost and convenience of handling 
must be considered. The user of lime is not concerned 
with the cost of transportation by the railroad so long as the 
delivered price shows the cost of actual lime to be reason- 
able. The cost of handling after the lime arrives at the rail- 
road station is the next important consideration. The con- 
centration, ease of handling, storage and distribution, and 
the probable cost of each operation are items of practical sig- 
nificance. In general, the less concentrated forms may be 
handled with greater ease and less expense, but the cost of 
cartage is practically doubled and it might be better to pur- 
chase one of the more concentrated forms, especially if the 
farm is located at considerable distance from the railroad. 

As a factor of cost, fineness of division should not be 
overlooked. Good burned lime showing a relatively high 
percentage of actual lime, indicating comparative free- 
dom from impurities, properly slaked, is as fine a powder 
as it is possible to obtain and there need be no doubt of 



Lime and Calcium Compounds 151 

its immediate action. The fineness of ground limestone 
is entirely arbitrary with the manufacturer. The finer 
it is, the quicker and more complete will be the action. 
A guarantee of the size of particles is important and should 
be insisted upon before purchase. Ground limestone ca- 
pable of passing at least 75 per cent through a 100-mesh 
screen or sieve gives prompt action and is suitable for use 
in most cases. A still finer product is more prompt and 
a coarser product less prompt in action. If conditions are 
such as to warrant the use of the coarsely ground limestone, 
it has the advantage of costing less. 

Peculiar conditions often exist or arise which help to 
determine the form of lime to use regardless of the fore- 
going suggestions relating to purchase. Crops sensitive 
to alkaline soil conditions are injured less and thrive better 
when the slower acting carbonate is used. This has 
already been referred to in greater detail. For quick- 
growing crops requiring a soil rich in organic matter and 
available plant-food, burned lime is preferable because it 
brings about chemical changes of the organic plant-food 
more quickly, causing a rapid and succulent growth. 
One point of importance in this matter is the solubility 
of the different forms. The burned lime which is changed 
to the hydrated form by slaking is more soluble in water, 
and hence becomes distributed throughout the soil more 
readily than the carbonate. It is true that slaked lime 
changes to the carbonate form, but this change requires 
some time even under the most favorable conditions and 
during this period the slaked lime is more active chemically. 

Distribution of lime. (See Fig. 13, Plate VI.) 

Lime, no matter in what form, should be evenly dis- 
tributed and when possible uniformly worked into the 



152 Fertilizers 

surface soil. Burned lime should be worked into the sur- 
face soil as soon as practicable after application and before 
it has had time to change to the carbonate form. A uni- 
form distribution is not difficult when machinery is used. 
Lime distributers are very efficient and make a profitable 
investment. If no machinery is available and the lime is 
spread by shovel from the back of a wagon, the soil should 
be worked very thoroughly immediately after application. 

Analysis and guarantee. 

Nearly all states now require guarantees showing chemi- 
cal and mechanical analyses of all forms of lime, and the 
farmer should be careful in the purchase of lime to require 
such an analysis and guarantee. Such an analysis should 
show the form of lime, the percentage of actual lime, the 
percentage of magnesia, the impurities and the fineness 
of division in the case of carbonate of lime. 



CHAPTER IX 
PURCHASE OF FERTILIZERS 

Commercial fertilizers, in the form in which they 
are obtained by farmers, are made up of varying pro- 
portions of one or more products from each class of 
fertilizing materials described. That is, every manu- 
facturer is obliged to go to these sources of supply, what- 
ever may be the name given to the finished product or 
mixture. Hence the fertilizing materials described are 
not regarded as commercial fertilizers in the same light 
as those which they are able to purchase under brand 
names from their local dealers. In the first place, a 
specific fertilizing material, as distinct from a manufac- 
tured fertilizer, contains, as a rule, but one of the essen- 
tial fertilizing elements, and its use under average condi- 
tions would be far different from one which contains two 
or all of the essential fertilizing elements. The materials, 
therefore, are classed as nitrogenous, phosphatic and 
potassic, according to whether the material contains nitro- 
gen, phosphoric acid or potash as its chief or its only 
constituent element; and these different classes, too, 
may be again subdivided into two distinct groups, the 
first including "standard," or high-grade materials, 
and second, "general," or low-grade materials. This 
classification is of the utmost importance. 

153 



154 Fertilizers 



STANDARD HIGH-GRADE MATERIALS 

Nitrate of soda, sulfate of ammonia and dried blood 
are, for example, standard or high-grade nitrogenous 
materials, and belong to the first group. They are " stand- 
ard" because they do not vary widely in their composi- 
tion. A definite quantity can be depended upon to fur- 
nish not only practically the same amount of the specific 
constituent, but to furnish it in a distinct and definite 
form, which is identical, from whatever source derived. 
For example, commercial nitrate of soda does not vary 
materially in its composition, and the nitrogen in it is 
always in the form of a nitrate. The same is true of sul- 
fate of ammonia. One ton will furnish practically as 
much nitrogen as any other ton, and it is always in the 
form of ammonia. It is also practically true of high- 
grade dried blood. Each lot contains this specific form 
of organic nitrogen, and will always decay at practi- 
cally the same rate, if used under the same conditions. 
They are also high-grade products because they are richer 
in the constituent element, nitrogen, than any other, 
and because this element is immediately or quickly avail- 
able. 

The South Carolina, Florida and Tennessee rock phos- 
phates differ from the nitrogenous materials mentioned, 
inasmuch as, in their raw state, they are not directly 
useful as fertilizers, — they are not sources of available 
phosphoric acid. Hence the standard supplies of phos- 
phoric acid are derived from these materials after they 
are manufactured into superphosphates. The various 
kinds of these may be regarded as high-grade in the sense 
that they always possess a high content of available phos- 
phoric acid. They are standard, too, not only because 



Purchase of Fertilizers 155 

of this, but because they do not vary widely in their com- 
position. A definite amount from each class can be 
depended upon to furnish practically the same amount 
of available phosphoric acid. For example, a ton of 
South Carolina rock superphosphate, from whatever 
manufacturer obtained, will not vary widely in its con- 
tent of phosphoric acid, and will always act in the same 
way under similar conditions. The various German 
potash salts are also standard and high-grade, since the 
composition of each grade and kind is practically uniform 
in its content of potash, which will always act in the same 
way under the same conditions, and since they are richer 
in the specific element, potash, than other potassic com- 
pounds suitable for the manufacture of fertilizers. 

These various standard, high-grade products, when 
used in the manufacture of fertilizers, make what are 
called "chemical fertilizers," because they are really 
crude chemical compounds, and furnish the particular 
fertilizer elements in their most concentrated and active 
forms. 



FERTILIZING MATERIALS WHICH ARE VARIABLE IN COM- 
POSITION 

The products which are included in the second group 
differ from the others, in that they not only vary in their 
content of the specific constituent, or in their composition, 
but they are also variable in the sense that the constitu- 
ents contained in them do not show a uniform rate of 
availability. For example, ground bone varies in its 
composition owing to its source and the method of treat- 
ment, and the availability of the constituents, nitrogen 
and phosphoric acid, also varies because of these condi- 



156 Fertilizers 

tions, and because of its mechanical condition or degree of 
fineness. Different samples of bone derived from the 
same source, treated in the same way, and ground to the 
same degree of fineness, would be regarded as standard, but 
because these conditions differ, bone from different sources 
cannot be depended upon to act in the same way under 
the identical climatic and soil conditions. This is also 
true of tankage, which varies, not only in the total amount 
of the constituents contained in it, but in the proportion 
of its two chief constituents, nitrogen and phosphoric 
acid, and in the rate at which they become available to 
plants. In this class belong, in addition to the bone and 
tankage, ground fish, and the various miscellaneous 
products. They cannot be depended upon, either in 
respect to their composition or their availability of the 
essential constituents — important advantages possessed 
by the standard products. 

HIGH-GRADE AND LOW-GRADE FERTILIZERS 

The fertilizers manufactured from these two classes 
of raw materials will therefore differ. Those made 
from the first class are always high-grade, both in refer- 
ence to the quality and quantity of the constituents that 
may be contained in a mixture. Those manufactured 
from the second group are not high-grade, so far as the 
form of the constituent is concerned, though they may 
be high-grade in the sense that they contain large amounts 
of them. In the manufacture of fertilizers, too, as a rule, 
all three of the essential constituents are introduced, and 
the buying of a fertilizer is really the buying of the three 
constituents, nitrogen, phosphoric acid and potash. 
Hence, the more concentrated the product, or the richer 



Purchase of Fertilizers 157 

it is in these constituents, the less will be the actual cost 
of handling per unit of the constituents desired, and the 
higher the grade of the materials used, the greater the 
proportionate activity of the constituents. 

The "unit" basis of purchase. 

In commercial transactions in fertilizing materials, 
two systems of purchase are used. The first is known 
as the "unit" system, in which case the quotations, or 
prices are based on the unit. A unit means one per 
cent on the basis of a ton, or 20 pounds. For example, 
a unit of available phosphoric acid means 20 pounds, and 
a quotation of $1 a unit would be equivalent to a quota- 
tion of 5 cents a pound. In the trade, sales are always 
made on this basis. The system is also applied to such 
nitrogenous products as blood, meat, hoof meal, concen- 
trated tankage and the like. The price is fixed at so 
much a unit of ammonia. This system is probably the 
most perfect, and certainly cannot but be satisfactory to 
both the dealer and the consumer. It results in the 
consumer receiving exactly as much as he pays for, and 
the producer is paid for exactly what he delivers. The 
number of units in each material sold is fixed in each 
case by the chemist to whom the samples are referred. 

The "ton" basis of purchase. 

The other method of purchase is known as the "ton " 
basis, and is used almost exclusively in the sale of other 
materials than the standard products mentioned, and 
manufactured fertilizers. This system works well with 
standard high-grade products, since the ton price is, in 
this case, a fair guide as to the cost of the constituents, 
though it cannot be as satisfactory as the other, since 



158 Fertilizers 

even the best materials may vary sufficiently to cause a 
difference in actual cost of the constituents, even though 
the price per ton remains unchanged. In this method, 
the products are usually accompanied by a guarantee, 
the purpose of which is to indicate the minimum amount 
of the constituents contained in the material. 

The necessity of a guarantee. 

In the purchase of mixtures, consumers should demand 
that they be accompanied by a guarantee, because they 
are unable to determine the kind and proportion of the 
different materials entering into the mixture, either by 
its appearance, weight or smell. In mixing, too, an 
opportunity is afforded for disguising poor forms of the 
constituents, particularly nitrogen. That is, in a mixture 
of nitrogenous materials, potash salts and superphosphates, 
it would be a difficult matter to determine, by mere phys- 
ical inspection, the proportion of the nitrogen which had 
been supplied in the form of horn meal and of blood, and 
the statement of the manufacturer on this point would 
be valuable in proportion to his reliability. The fact that 
in mixtures it is impossible for the consumer to distinguish 
or determine the proportions, amounts or kinds of the 
constituents is so fully recognized that it has resulted in 
the enactment of laws in most states, which require that 
manufacturers or dealers in fertilizers shall state the actual 
amounts of the different constituents contained in their 
products, as well as the sources from which they were 
derived, and which fix a penalty for any failure to comply 
with the law in this respect. A chemical control is in 
these cases provided for, and it has been of great service 
both to the good manufacturers, because it tends to reduce 
the number of low-grade brands which would naturally 



>1 





Purchase of Fertilizers 159 

come into competition with them without such protection, 
and to the consumers, because it protects them from frau- 
dulent products. 

Laws alone do not fully protect. 

Laws alone, however, are not sufficient to fully protect 
the farmer in this respect. He must possess, in addition, 
a knowledge of what constitutes a good fertilizer, and 
must be able to determine from the analysis whether 
there is a proper relation between the guarantee and the 
selling price, and whether the materials that have been 
used are of good quality. The fact that there is a very 
decided lack of the right sort of intelligence on this point, 
is shown by the results of the work of the different ferti- 
lizer control stations. These demonstrate clearly that 
farmers do, in many cases, pay exorbitant prices for their 
fertilizer constituents, not because the manufacturer did 
not sell what he claimed to sell, but because the price 
charged by the dealer was far in excess of that warranted 
by the guarantee. For example, it has been repeatedly 
shown that of two farmers in the same neighborhood, the 
one who studies the matter and understands the relation 
of guarantee to selling price, may pay 15 cents a pound 
for his nitrogen, while the other, who does not study the 
matter, buys on the ton basis, and does not know that 
there should be such a relation between the two, may pay 
30 cents a pound for the same quality of the same constit- 
uent. This may be illustrated by the following examples : 

Two brands are offered, made up from the same kind 
and quality of materials. No. 1 is guaranteed to contain : 

Nitrogen 1% 

Phosphoric acid (available) 6% 

Potash 1% 



160 Fertilizers 

and sells for $20 a ton ; and No. 2 is guaranteed to con- 
tain: 

Nitrogen 4% 

Phosphoric acid (available) 8% 

Potash 2% 

and sells for $22 a ton. The farmer who buys on the 
ton basis, or is guided only by the ton price, will be in- 
duced to purchase the No. 1 brand, because by so doing 
he apparently saves $2 a ton. The one who studies the 
relation of guarantee to selling price will purchase the 
No. 2 brand, because he finds, from a simple calculation, 
that it furnishes the constituents at just one-half the cost 
per pound of the No. 1 brand, notwithstanding the higher 
ton price, which is shown by the following calculation : 

No. 1 

Lbs. Cts. 

to the ton to the lb. 

Nitrogen 1 % X 20 = 20 @ 30 = $6 00 

Phosphoric acid (available) 6% X 20 = 120 @ 10 = 12 00 

Potash 1%X20= 20 @ 10 = 2 00 

$20 00 
No. 2 

Lbs. Cts. 

to the ton to the lb. 

Nitrogen 4% X 20 = 80 @ 15 = $12 00 

Phosphoric acid (available) 8% X 20 = 160 @ 5 = 8 00 
Potash 2% X 20 = 40 @ 5 = 2 00 

$22 00 

In reality, the fertilizer at $22 a ton is cheaper than the 
one at $20 a ton. 

No. 1 No. 2 

Nitrogen $0 30 $0 15 

Phosphoric acid (available) . . 10 05 

Potash 10 05 

This may seem an extreme case, but it is well within 
the facts, which may be ascertained by consulting the 



Purchase of Fertilizers 



161 



bulletins on fertilizer analyses, as published by the dif- 
ferent states. 

Method of statement of guarantee sometimes misleading. 

Guarantees, too, are sometimes rendered confusing 
to the purchaser because of the method of their state- 
ment, though the different methods used are, in one sense, 
entirely legitimate, because the terms used are in accord- 
ance with the facts. From a chemical standpoint, at 
any rate, it is quite as legitimate to guarantee the per- 
centage of phosphoric acid equivalent to bone phosphate 
of lime, as it is to guarantee the percentage of actual 
phosphoric acid. It is because the consumer believes 
that the "equivalent" in combination means that he is 
obtaining something more than when actual constituents 
only are guaranteed, that he is led to purchase more freely, 
or to pay a higher price. Nitrogen may be properly 
stated in its equivalent of ammonia, phosphoric acid 
in its equivalent of bone phosphate, and potash in its 
equivalent of muriate of potash, and it is the business of 
the purchaser to understand the relations of the two 
methods of statement, in order that he may not be mis- 
led in his purchases. The following table shows the terms 
used, their equivalents, and the factor to use in multiply- 
ing, in order to convert the one into the other : 



To convert the guarantee of 

Ammonia . 
Nitrogen . . . 
Nitrate of soda . 
Bone phosphate . 
Phosphoric acid . 
Muriate of potash 
Actual potash 
Sulfate of potash 
Actual potash 



into an 

equivalent 

of 



Nitrogen . . . 
Ammonia . . . 
Nitrogen . . . 
Phosphoric acid 
Bone phosphate . 
Actual potash . 
Muriate of potash 
Actual potash . 
Sulfate of potash 



Multiply by 

. 0.8235 

. 1.214 

. 0.1647 

. 0.458 

. 2.183 

. 0.632 

. 1.583 

. 0.54 

. 1.85 



162 Fertilizers 

Discussion of guarantees. 

It is shown in this table that, in order to convert am- 
monia into its equivalent of nitrogen, the percentage 
of ammonia should be multiplied by 82 per cent, or di- 
vided by the factor 1.214, because ammonia is 82 per 
cent nitrogen, and because one part of the nitrogen is 
equivalent to 1.214 parts of ammonia. 

In order to determine the cost of a pound of ni- 
trogen in dried blood, which is quoted, for example, 
at $3 a " unit," — 20 pounds of ammonia, — the unit 
20 pounds is multiplied by 82 per cent, which gives 
16.40 as the pounds of nitrogen offered for $3, or 18.3 
cents a pound. 

Bone phosphate of lime is, in round numbers, 46 
per cent actual phosphoric acid. Hence, by multiply- 
ing the bone phosphate by 46 per cent, the percent- 
age of actual phosphoric acid is obtained. Ground 
bone, for example, guaranteed to contain from 48 to 
52 per cent bone phosphate, contains, in round num- 
bers, 22 to 24 per cent of phosphoric acid. Sulfate 
of potash is 54 per cent, and muriate of potash is 63 
per cent "actual" or potassium oxide, respectively. 
Hence, to convert the percentages of these forms into 
their equivalents of "actual," they are multiplied by 
the factors given. 

In such raw materials as nitrate of soda, muriate of 
potash and sulfate of potash, a method of guaranteeing 
is used which is based upon their purity as chemical salts. 
That is, when pure they contain 100 per cent of the specific 
salt, and the guarantee accompanying the commercial 
product is simply a statement indicating their purity. 
For example, when nitrate of soda is guaranteed to con- 



Purchase of Fertilizers 163 

tain from 95 to 97 per cent pure nitrate, it means that it is 
95 to 97 per cent pure, or that 3 to 5 per cent of the sub- 
stance consists of impurities; it is not absolutely pure 
nitrate of soda. Hence, the minimum percentage of 
nitrogen guaranteed is 15.65 per cent, or 95 per cent of 
16.47, the per cent or pounds in each hundred of nitrogen 
contained in pure nitrate of soda. When muriate of potash 
is guaranteed 80 per cent muriate, it means that 80 per 
cent of the salt consists of pure muriate of potash, and 
because pure muriate of potash contains 63 per cent of 
actual potash, or potassium oxide, the actual content of 
potash is derived by multiplying the 63 per cent, which 
the pure salt contains, by 80 per cent, and the result, 50.5 
per cent, represents the amount of actual potash guaran- 
teed. Sulfate of potash, high-grade, is usually guaranteed 
to be 98 per cent pure, and since pure sulfate of potash 
contains 54 per cent of actual potash, the content of actual 
potash, or potassium oxide, guaranteed is found by mul- 
tiplying the 54 per cent by 98 per cent. The following 
illustrations show the two methods of stating the guar- 
antees of raw materials and of mixed fertilizers : 

Raw materials. 

Guarantee on Basis of Purity 

Nitrate of soda . . . 98%, or containing 98% pure nitrate 

Muriate of potash . . 80%, or containing 80% pure muriate 

Sulfate of potash . . 98%, or containing 98% pure sulfate 

Kainit 25%, or containing 25% pure sulfate 

Guarantee on Basis of Actual Constituents 

Nitrate of soda, total nitrogen 16.00% 

Muriate of potash, actual potash 50.50% 

Sulfate of potash, actual potash 53.00% 



164 Fertilizers 

Mixed fertilizers. 

Guarantee on Basis op Equivalents in Combination 

Nitrogen (equivalent to ammonia) 3 to 4% 

Available phosphoric acid (equivalent to bone phos- 
phate of lime) 18 to 22% 

Potash (equivalent to sulfate of potash) . . . . 10 to 12% 

Guarantee on Basis of Actual Constituents 

Nitrogen (total) 2.50 to 3.25% 

Phosphoric acid (available) 8.00 to 10.00% 

Potash (actual) 5.50 to 6.50% 

The guarantees of the raw materials mean practically 
the same in the first as in the second case. In the first, 
the percentages given indicate the purity of the chemical 
salt; while in the second, the figures given indicate the 
actual content of the constituent contained in the chemical 
salt. In large commercial transactions, the sales are 
frequently made on the basis of certain purity percentages ; 
as, for example, muriate of potash is sold at so much a 
ton on the basis of 80 per cent muriate. If the analysis 
shows it to contain less than 80 per cent, then the price 
paid per ton is less in proportion to such deficiency. 
If it is shown to contain more than 80 per cent, the pur- 
chaser pays for the excess at the same rate. In round 
numbers, a ton of muriate on the 80 per cent basis con- 
tains 1000 pounds of actual potash; if the price is $40 
a ton, the cost a pound is 4 cents. If analysis shows but 
900 pounds instead of 1000, the price paid a ton, at 4 
cents a pound, is S36. If, on the other hand, it is shown to 
contain 1110 pounds, the price paid a ton is $44. Pur- 
chase made when this method of guaranteeing is used is 
practically equivalent to the "unit" basis, though, as 



Purchase of Fertilizers 165 

already stated, unless it is thoroughly understood, it is 
likely to be misleading. 

What has been said of the different statements of guar- 
antees of the raw materials, is also true in the case of the 
mixed goods. In the first, the percentages of the elements 
that are given represent the amounts when they exist 
in combination with other elements : nitrogen, as am- 
monia; phosphoric acid, as bone phosphate; and potash, 
as sulfate. While in the other, the percentages given 
indicate the content of the actual constituents; namely, 
nitrogen, phosphoric acid and potash. 

The advantages and disadvantages of purchasing raw mate- 
rials and mixed fertilizers . 

In the purchase of fertilizers, therefore, two methods 
may be adopted : First, the buying of fertilizing materials, 
as distinct from fertilizers, which furnish single constitu- 
ents like the standard high-grade products, or which fur- 
nish one or two of the constituents, like ground bone, tank- 
age, fish and the miscellaneous products ; these are called 
"incomplete," because they do not furnish all of the three 
essential constituents. Second, the purchase of the mixed 
manufactured brands, which contain all of the three essen- 
tial constituents, nitrogen, phosphoric acid and potash, 
which are prepared to meet the demands of different soils 
and crops, and are called "complete," because containing 
all of the essential manurial constituents, or those liable 
,to be lacking in any soil. The relative advantage of these 
different methods of purchase depends, first, upon the cost 
of the constituents, and second, upon the use that is to be 
made of them. 

It may be urged that, on theoretical grounds, there 
are no good reasons why nitrate of soda, sulfate of am- 



166 Fertilizers 

monia, dried blood, superphosphates and potash com- 
pounds should be mixed, as the manufacture of these does 
not improve or change the quality of the constituents 
— it consists chiefly in simply grinding, mixing and bag- 
ging. There are, however, advantages and disadvantages 
in both methods of purchase, the chief of which are stated 
below. 

The advantages in the purchase and use of raw materials 
are: * 

1. A better knowledge of the kind and quality of 
plant-food obtained. That is, these products as a rule 
possess characteristics which distinguish them from 
others and from each other, and they are more likely to 
be uniform in composition than mixtures. 

2. It enables the use of one or more of the constituents 
as may be found necessary, thus avoiding the expense of 
purchasing and applying those not required for the par- 
ticular crop or soil. The farmer is also enabled to adjust 
the forms and proportions of the various ingredients to suit 
what he has found to answer the needs of his soil or crop. 

3. A saving in the cost of plant-food, since in their 
concentrated form, the expenses of handling, mixing and 
rebagging are avoided. 

The chief disadvantages are : 

1. The materials are not generally distributed among 
dealers, and thus not so readily obtained. 

2. It is difficult to spread evenly and thinly products 
of so concentrated a character, particularly the chemical 
salts, which, unless great care is used, may injure by com- 
ing in immediate contact with the roots of plants. 

3. The mechanical condition or degree of fineness is 
less perfect than in the manufactured products. 

1 " First Principles of Agriculture." 



Purchase of Fertilizers 167 

The advantages in the purchase and use of complete 
manures are : 

1 . They are generally distributed, and can be purchased 
in such amounts and at such times as are convenient. 

2. The different materials may be well proportioned, 
both as to form of the constituents and their relative 
amount for the various crops. 

3. The products are, as a rule, finely ground and well 
prepared for immediate use. 

The chief disadvantages are : 

1. That it is impossible to detect in a mixture whether 
the materials are what they are claimed to be. 

2. That without a true knowledge of what constitutes 
value, many are led to purchase on the ton basis, without 
regard to the quantity and quality of the plant-food 
offered. 

There is no question that the actual cost of the con- 
stituent is less when purchased in the fertilizing material 
than in the manufactured brand, as not only the expenses 
of mixing and bagging are saved, but the cost of handling 
the product per unit of plant-food is much less in the highly 
concentrated materials than in mixtures made up of both 
classes of fertilizing materials. 

In the purchase of fertilizers by the second method, 
the cost of the constituents is not only higher on the 
average, but the variations in their cost are very much 
greater, due to the differences in the charges made by the 
different manufacturers for handling and selling their 
products. 

HOME MIXTURES 

The fact that fertilizing materials are a regular article 
of trade, and may be purchased as such, and the fact that 



168 Fertilizers 

a complete fertilizer, so called, is really only a mixture of 
the various manufactured fertilizing materials, has sug- 
gested the use of what are called "home mixtures," — 
that is, their mixing by the farmer himself. This has 
proved to be very satisfactory under proper conditions, 
since, as already stated, the cost of the constituents is 
much less than if secured in the average manufactured 
brand (often from 25 to 50 per cent), and the mixing can 
be performed by the regular labor of the farm, and thus 
not add directly to the cost of the constituent. 

This matter of home mixtures has been carefully 
studied by a number of the experiment stations, notably 
Connecticut, Rhode Island and New Jersey. The re- 
sults of their studies are published in their regular reports, 
and show that the materials can be evenly mixed on the 
farm, that the mechanical condition is good and that the 
results obtained from their use are entirely satisfactory. 
It must be remembered, however, that whatever method 
of purchase is used, the object should be to obtain the kind 
and form of constituent best suited to the conditions under 
which they shall be used, at the lowest price a pound. 

In any method of purchase which contemplates the 
use of a mixture, care should be taken in the selection of 
the brand or of the formula, since in mixtures as well as 
in the raw materials, there are two grades, the high-grade 
and the low-grade — high-grade in the sense that in 
quality the constituents are all good, and in the sense that 
maximum quantities are contained; and second, high- 
grade only in that constituents of good quality are fur- 
nished. They may be low-grade in the sense that both 
the quality and amount of constituents contained are 
low, and also in the sense that only the quality of the 
constituents is low, the quantity being sufficiently high. 



Purchase of Fertilizers 



169 



Formulas. 

The following formulas are used for the sole purpose 
of illustrating the differences that may exist between 
high-grade and low-grade mixtures, and not as indicating 
what should be used to make a good or poor mixture. 



Formula No. 1 

Pounds 



Amount Material 

500 lbs. nitrate of 
soda contains 

1100 lbs. acid phos- 
phate contains 

400 lbs. muriate of 
potash contains 



Ammo- Phos. 
nia Acid 



Potash 



Plant- 
food 



Price 
100 Lbs. 



Cost 



80 — — 80 costs $2.50 = $12.50 

— 180 — 180 costs .60 = 6.60 

— — 200 200 costs 2.00 = 8.00 



2000 lbs. mixture 

contains 80 180 200 460 and costs 

-^ 20 = 100 lbs. mix- 
ture contains 4.0 9.0 10.0 — and costs 

Guaranteed com- 
position 4.0 9.0 10.0 — 



$27.10 
1.355 





Formula 


No. 


2 




250 lbs. nitrate of 












soda contains 


40 


— 


— 


40 costs $2.50 = 


$6.25 


1000 lbs. acid phos- 












phate contains 


— 


160 


— 


160 costs .60 = 


6.00 


80 lbs. muriate of 












potash contains 


— 


— 


40 


40 costs 2.00 = 


1.60 


670 lbs. make- 












weight or filler 


— 


— 


— 


— 




2000 lbs. mixture 












contains 


40 


160 


40 


240 and costs 


$13.85 


-=- 20 = 100 lbs. 












mixture contains 


4.0 


8.0 


2.0 


— and costs 


.69 



Guaranteed com- 
position 4.0 8.0 2.0 



170 



Fertilizers 



Amount Material 

600 lbs. tankage 

contains 30 

400 lbs. kainit contains — 

1000 lbs. make- 
weight contains — 



Formula No. 3 

Pounds 

Ammo- Phos. r>„i.„„u Plant- 
nia Acid Potash food 



Price 
100 Lbs. 



Cost 



90 



50 



120 costs 
50 costs 



.60 = $9.60 
.65 = 2.60 



2000 lbs. mixture 

contains 30 90 50 170 and costs 

-J- 20 = 100 lbs. 

mixture contains 1.5 4.5 2.5 8.5 and costs 
Guaranteed 

composition 1.5 4.5 2.5 — 



$12.20 
.61 



Formula No. 4 

1200 lbs. tankage 

contains 60 180 

800 lbs. kainit con- 
tains — — 100 100 costs 



240 costs $1.60 «= $19.20 
65 = 5.20 



2000 lbs. mixture 

contains 60 180 100 340 and costs 

■f 20 = 100 lbs. 

mixture contains 3.0 9.0 5.0 17.0 and costs 
Guaranteed 

composition 3.0 9.0 5.0 



$24.40 
1.22 



Formula No. 1 shows a high-grade product, both in 
respect to quality of plant-food and concentration, while 
No. 2 is high-grade only in respect to quality. In order 
that the plant-food may be distributed throughout a ton 
of material, it is necessary to add what is called "make- 
weight," or a diluent. These usually consist of substances 
that possess no direct fertilizing value. High-grade 
mixtures cannot be made from low-grade materials, and 



Purchase of Fertilizers 171 

low-grade mixtures cannot be made from high-grade 
materials without adding "make-weight." The advan- 
tages of high-grade products are concentration and high 
quality of plant-food. 

It will be observed that formula No. 1 contains nearly 
twice as much plant-food as No. 2, or, in other words, it 
will require about two tons of a fertilizer made according 
to formula No. 2 to secure the same total amount of plant- 
food as is contained in one ton of No. 1. Now, the mate- 
rial in No. 2, other than the actual plant-food, is of no 
direct fertilizing value, — it is of no more value as a fer- 
tilizer than the soil to which it is applied, — but the actual 
cost of the constituents is considerably increased, because 
the expenses of handling, bagging and shipping are just 
double what they would be for No. 1. 

Formula No. 3 illustrates a low-grade fertilizer in 
the sense that it contains the poorer forms of the con- 
stituents, and furnishes a comparatively small total 
amount of plant-food. The nitrogen is all in the organic 
form, and is derived from tankage, which, while not the 
poorest, is poorer than other forms of organic nitrogen. 
The phosphoric acid is also in organic combination, and, 
while useful under many conditions, is less useful for cer- 
tain other conditions than the soluble in Nos. 1 and 2. 
The potash, while soluble, is derived from kainit, which, 
because of its large content of chlorin, is regarded as less 
desirable for certain crops than the more concentrated 
materials, muriate, or the high-grade sulfate, which is 
free from chlorids. It would require more than 2\ tons 
of a mixture made according to this formula to furnish 
as much total plant-food as would be contained in a mix- 
ture made according to formula No. 1, besides the dis- 
advantage of the lower quality of the constituents. 



172 Fertilizers 

Formula No. 4 illustrates a mixture which, while rich 
in total constituents, is not high-grade in its quality. 

All of these considerations should therefore be care- 
fully observed in the purchase of mixtures, or even in 
the purchase of raw materials for home mixtures, and the 
analysis, if properly made, will give positive evidence on 
these points. 

The expensiveness of low-grade fertilizers, as repre- 
sented by formulas Nos. 2 and 3, is not fully appreciated 
by the purchaser in all cases. He does not stop to think 
that it is quite as expensive to handle the material which 
contains no plant-food as it is to handle material which is 
rich in plant-food. 

The cost of handling "make-weight" 

A comparison of the advantages of low-grade and 
high-grade mixtures in this sense of total quantity of 
plant-food may be illustrated as follows: 

It has been shown by continued studies at the New 
Jersey Experiment Station that the charges of the man- 
ufacturers and dealers for mixing, bagging, shipping and 
other expenses are, on the average, $8.50 a ton ; and also 
that the average manufactured fertilizer contains about 
300 pounds of actual fertilizing constituents to a ton. 
A careful study of the fertilizer trade indicates that these 
conditions are also practically true for other states in which 
large quantities of commercial fertilizers are used. 

A mixture of formula No. 1 would contain 460 pounds 
of actual available fertilizing constituents in each ton 
— 160 pounds, or over 50 per cent more than is contained 
in the average manufactured brand. That is, a farmer 
purchasing a brand similar to formula No. 1 would secure 
in 2 tons as much plant-food as would be contained in 



Purchase of Fertilizers 173 

3 tons of the average manufactured brand. Assuming 
that the charges per pound of plant-food at the factory, 
and the expense charges, are the same in each case, and 
also that the quality of plant-food in the one is as good 
as in the other, the consumer would save $8.50 by purchas- 
ing 2 tons of the former instead of 3 tons of the 
latter. In a few states the consumption of fertilizers 
reaches nearly 100,000 tons annually, while in many it 
ranges from 30,000 to 50,000 tons. 

Thus is shown the very great saving that may be 
effected in the matter of the purchase of fertilizers from 
the standpoint of concentration alone, or, in other words, 
the importance of a definite knowledge of what constitutes 
value in a fertilizer. This saving may be accomplished, 
too, without any detriment to the manufacturer, since 
the difference to him between making high-grade or low- 
grade goods, in reference to concentration, is largely a 
matter of unskilled labor. The manufacturers are in 
the business to cater to the demands of the trade. If 
consumers are intelligent, high-grade rather than low- 
grade goods will be provided by the manufacturers. 
Furthermore, as already indicated, high-grade in the 
matter of concentration means high-grade in quality, 
for high-grade mixtures cannot be made from low-grade 
products. 

GENERAL ADVICE 

As farmers understand more fully the question of 
fertilization, and as intensive methods of practice are 
adopted, the tendency in the purchase of fertilizers will 
undoubtedly be toward the first method, or the purchase 
of fertilizing materials, rather than mixtures, or at any 
rate, of high-grade special mixtures, rather than what 



174 Fertilizers 

are now termed "standard brands," which are, as a rule, 
low-grade in the concentrated sense. This tendency 
will come, first, because intensive practice requires a larger 
use of all of the constituents, and second, a greater need 
in the growth of certain crops of specific or dominant 
elements, and thus better results are obtained from the 
application of single constituents, or the use of special 
formulas, than in "extensive" practice, in which the ob- 
ject is more to supplement the soil supplies than to fully 
provide for all the needs of the plants for food. 

The tendency toward cooperative buying on the part 
of small farmers will increase as it has done in those coun- 
tries in which there is a larger use of fertilizers than here, 
though the method is already in successful operation in 
certain sections of the country, and with very gratifying 
results. In this method of direct purchase, the manu- 
facturer and the consumer are brought into closer rela- 
tions with each other. Transactions are based upon the 
transfer of a definite number of pounds of a specific kind 
and form of plant-food, rather than upon some myste- 
riously remarkable qualities that are claimed, and are by 
many supposed to be inherent in certain mixtures. 



CHAPTER X 

CHEMICAL ANALYSES OF FERTILIZERS 

A complete chemical analysis of a fertilizer shows 
not only the total amount of the different constituents 
contained in a brand, but the form in which they exist, 
and in most cases, the source of the materials used is also 
indicated. 

THE INTERPRETATION OF AN ANALYSIS 

An analysis may show simply the total amount of 
the constituents. This is not a sufficient guide as to 
the value of a mixture, for while it is not possible to 
indicate absolutely by analysis whether the organic 
nitrogen, for example, is derived from blood (which is 
one of the best forms), or from horn meal (one of the 
poorer forms), it is possible to show whether the nitro- 
gen is derived from nitrate or from ammonia, whether 
the phosphoric acid is derived from a superphosphate 
or a phosphate, and whether the potash present is in 
the form of a sulfate or of a muriate. A high-grade 
or a low-grade fertilizer, for example, may be distinctly 
indicated by the analysis, since it is of a high-grade 
if the three forms of nitrogen are present, if the total 
phosphoric acid is chiefly soluble in water, and if the 
potash has been derived from a sulfate or from a 
muriate. On the other hand, if the analysis shows 

175 



176 Fertilizers 

that the nitrogen is all in the organic form, that only 
a minimum percentage of the phosphoric acid is available, 
though not soluble, and that a high content of chlorin 
accompanies the potash, it is a low-grade product, in so 
far as the form of the constituents is concerned. The 
following statements of analyses of two brands, showing 
the same total content of constituents, illustrate this 
point : 

Analysis No. 1 

Nitrogen, as nitrate 1 % 

Nitrogen, as ammonia 1% 

Nitrogen, as organic matter ... 1% 

Total 3% 

Phosphoric acid, soluble .... 8% 
Phosphoric acid, reverted .... 1% 
Phosphoric acid, insoluble .... 1% 

Total available 9% 

Potash 5% 

Chlorin 0.50% 

Analysis No. 2 

Nitrogen, as nitrate 

Nitrogen, as ammonia 

Nitrogen, as organic matter . . . 3% 

Total 3% 

Phosphoric acid, soluble .... 
Phosphoric acid, reverted .... 2% 
Phosphoric acid, insoluble . ... 8% 

Total available 2% 

Potash 5% 

Chlorin 10% 

A study of these two statements of analyses shows 
that the total contents of the constituents are identical, 
3, 10 and 5, respectively, in each case. That is, so 
far as the total amounts are concerned, one brand fur- 
nishes as much as the other, and from that standpoint 



Chemical Analyses of Fertilizers 177 

alone it is as good as the other ; but it has been already 
shown that the value of a fertilizer depends not only upon 
the total content of its constituents, but upon the form 
in which they exist. In the first brand it is found that two- 
thirds of the total nitrogen exists in the soluble form, 
equally divided between nitrate and ammonia ; the re- 
maining third is in the organic form, and may be derived 
from blood, or from some low-grade materials. It is to be 
fairly presumed, however, that when thus associated with 
so high a proportion of soluble nitrogen, it is in a good 
form, as the manufacturer has given evidence of his intent 
by his liberal use of other good forms. 

In the case of the phosphoric acid, it is shown that 
of every 100 pounds of the total, 80 pounds are soluble, 
10 reverted, or nine-tenths of the whole is available ; 10 
pounds of every hundred only are insoluble, which is not 
only an indication, but positive proof, that the phosphoric 
acid is derived from a superphosphate. 

In the case of potash, the chlorin associated with it 
is but \ per cent, indicating that it has been drawn from 
high-grade sulfate, since kainit and muriate are rich in 
chlorin, while in a high-grade sulfate no appreciable 
amounts of chlorin are present. 

In the second statement, all of the nitrogen is shown 
to be in the form of organic matter. It may be derived 
from blood, though it is not likely to have been drawn 
from this source, since of the total phosphoric acid but 
20 pounds to the hundred, or one-fifth, is available, and 
that is reverted rather than soluble, indicating that the 
phosphoric acid must have been drawn from tankage or 
from bone, or other materials which contain reverted but 
no soluble phosphoric acid, and which also contain a con- 
siderable percentage of nitrogen. The phosphoric acid 



178 Fertilizers 

was certainly not drawn from a superphosphate, or it 
would have shown a higher percentage of available, a cer- 
tain proportion of which whould have been soluble, and 
the percentage of insoluble would have been very much 
less. In the case of potash, it is quite evident that it was 
drawn from kainit, inasmuch as the percentage of chlorin 
exceeds the percentage of the potash, as would be the case 
if the potash had been drawn from that source. 

Thus it is that a complete chemical analysis of a fer- 
tilizer indicates very clearly the source of the materials 
by the form in which the constituents exist in the mixture. 

THE AGRICULTURAL VALUE OF A FERTILIZER 

It is obvious, from what has already been pointed 
out, that the value of a fertilizer to the farmer depends 
not so much upon what is paid for it as upon the character 
of the materials used to make it. This value is termed 
the " agricultural value," and it is measured by the value 
of the increased crop produced by its use. It is, therefore, 
a variable factor, depending first, upon the availability of 
its constituents, and second, upon the value of the in- 
creased crop produced. 

For example, in the first place, the agricultural value of 
a pound of soluble phosphoric acid is likely to be greater 
than that of a pound of insoluble when applied under the 
same conditions as to soil and crop, because in the one case 
the element is in its most available form, while in the 
other it is least available. In the second place, the solu- 
ble phosphoric acid may exert its full effect and cause 
a greatly increased yield on a certain crop, and still not 
cause an increase in its value sufficient to pay the cost of 
the application, while for another crop the same applica- 



PLATE VIII. — Wheat and Timothy. 




Fig. 15. — • Thirty-five Bushels of Wheat to the Acre, Mechan- 
icsburg, Pennsylvania. 




*>§&**■ 



JS^SJ£e*' ; 




Fig. 16. — Early Spring Top-dressing with Commercial Ferti- 
lizer High in Available Nitrogen Greatly Increases the 
Yield of Timothy. 



Chemical Analyses of Fertilizers 179 

tion may result in a very great increase in the value of 
the crop. The character or form of the materials used in 
a mixture, as well as their suitability for the crop must, 
therefore, be carefully considered in the purchase of fer- 
tilizers. Slow-acting materials cannot be expected to give 
profitable returns, particularly upon quick-growing crops, 
nor expensive materials such profitable returns, when used 
for crops of relatively low value, as for crops of relatively 
high value. 

THE COMMERCIAL VALUE OF A FERTILIZER 

This agricultural value, however, is separate and 
distinct from what is termed "commercial value," or 
cost in market. This value is determined by market 
and trade conditions, as the cost of production of the 
crude materials and the cost of their manufacture and 
sale. Since there is no strict relation between agricul- 
tural and commercial or market value of a fertilizer con- 
stituent, it frequently happens that an element in its 
most available form, and under ordinary conditions of 
high agricultural value, costs less in market than the same 
element in less available forms and of a lower agricultural 
value. The cost of production in the one case is lower 
than in the other, though the returns in the field are far 
superior. 

It is manifestly impossible to fix an agricultural value 
for any of the constituents that will be true under the 
varying conditions of soil, crop and season, and method of 
use, though the relative value of the different forms under 
uniform conditions of use may be fairly indicated, and the 
analysis is the guide as to their form. The commercial 
value of the different constituents in their various forms 



180 Fertilizers 

may, too, be fairly indicated, and will vary according to 
variations in trade conditions. If the wholesale jobbing 
price of nitrogen as nitrate is 15 cents a pound, available 
phosphoric acid 5 cents a pound, and potash 4 cents a 
pound, these are the prices which the manufacturers pay. 
Their increased cost in manufactured brands, therefore, 
is in proportion to the cost of this work ; hence their cost 
to the consumer at factory should vary within reasonably 
narrow limits, due to variations in cost of manufacturing 
in different localities. 

An illustration of the commercial value is shown by 
the following example : Suppose that nitrate of soda costs, 
or can be purchased at retail, in ton lots, for $48 a ton, 
which is, then, its commercial value. The commercial 
or trade value of the nitrogen is, therefore, 15 cents a 
pound, since a ton contains on the average 320 pounds 
of nitrogen. Or, suppose that the retail price of avail- 
able phosphoric acid in superphosphates is $1 a unit; 
this is its commercial value, and hence the commercial or 
trade value of the available phosphoric acid would be 5 
cents a pound, since a unit contains 20 pounds. It does 
not follow that the application of a pound of nitrogen 
costing 15 cents, and therefore having a commercial 
value of 15 cents, will result in an increased crop worth 
15 cents, or that the application of a pound of phosphoric 
acid costing 5 cents a pound will result in an increased 
crop worth 5 cents. The increased returns in crop from 
their use may be very much greater or much less than the 
cost of the constituents, depending upon the kind of crop 
and the skill of the user. In the purchase of materials, 
however, a commercial valuation is a guide as to the cost 
of the constituents from different manufacturers or dealers ; 
and in many states a system of commercial values for 



Chemical Analyses of Fertilizers 181 

mixed fertilizers has been fixed, which, when properly 
understood, is a useful method of comparison of the 
different brands. 

This method is based upon the fact that at points 
of supply a pound of nitrogen, in the form of nitrate, 
of ammonia or of definite organic compounds, or a 
pound of available phosphoric acid, or of potash in the 
form of muriate or sulfate, is practically the same to all 
manufacturers. That is, these cost prices, or trade values, 
when applied to the constituents in the mixture, represent 
their commercial value before they are mixed to form 
complete fertilizers. Hence, the difference between the 
valuation of a brand on this basis and the cost to the con- 
sumer represents the charges, including profit, for mixing, 
bagging, shipping and selling the goods. 

The commercial or trade value for each of these con- 
stituents is obtained, as already indicated, by simply 
calculating the cost, using two factors, — the wholesale 
prices for the different materials containing them, and 
their average composition. To this cost is added a cer- 
tain percentage, to represent the cost of handling and dis- 
tribution in small lots. Thus the trade value corresponds 
as nearly as may be with the cost of the constituents to 
the farmer. That is, the price fixed represents what the 
farmer would have to pay the manufacturer for the con- 
stituents in the material before it is mixed. 

For example, suppose the wholesale price a ton of 
nitrate of soda for the six months preceding March 1 is 
shown to be $40 ; the wholesale cost of nitrogen in this 
form is, therefore, 12.5 cents a pound. To this wholesale 
price may be added a certain sum to cover the expenses 
of handling, usually 20 per cent, thus making the retail 
price a ton $48, and the trade or commercial value of the 



182 Fertilizers 

nitrogen 15 cents a pound. That is, the $48 a ton, or 15 
cents a pound, represents the retail cost a pound of nitrate 
nitrogen. This, if applied to the nitrogen as nitrate, in 
the mixed fertilizer, will show what it could have been 
bought for as nitrate in the unmixed fertilizer. The 
values for the other constituents are derived in the same 
way. These, together, make the schedule of trade or com- 
mercial values of the constituents which are used in the 
computing of the commercial values of mixed fertilizers. 
The schedule of values is revised annually, and, as nearly 
as possible, at the same time in the year. The following 
schedule, used as an illustration of this point, was adopted 
by the Directors and Chemists of the Experiment Stations 
of New Jersey and the New England states for use in that 
territory for the year 1914 : 

Schedule op Trade Values Centa 

per pound 

Nitrogen in nitrates 16.5 

Nitrogen in ammonia salts 16.5 

Organic nitrogen in fine x ground fish, meat and blood . 22.5 

Organic nitrogen in cotton-seed meal and castor pomace 22.5 

Organic nitrogen in fine x bone and tankage 21.5 

Organic nitrogen in mixed fertilizers 19.5 

Organic nitrogen in coarse l bone and tankage .... 17.5 

Phosphoric acid, soluble in water 4.5 

Phosphoric acid, soluble in ammonium citrate .... 4.0 

Phosphoric acid in fine ' bone and tankage 4.0 

Phosphoric acid in cotton-seed meal and castor pomace 4.0 

Phosphoric acid in coarse 1 bone, tankage and ashes . . 3.5 
Phosphoric acid, insoluble in water and in ammonium 

citrate 2.0 

Potash in high-grade sulfate, and in the forms free from 

muriate (chlorids) 5.0 

Potash in muriate 4.0 

Potash in cotton-seed meal and castor pomace . . . 5.0 

1 "Fine" signifies such as will pass through a sieve with 
circular holes ifo of an inch in diameter, and "coarse" such as 
will not. 



Chemical Analyses of Fertilizers 183 

It will be observed that the schedule gives the cost 
a pound of the different forms of nitrogen, and of high- 
grade organic nitrogenous materials; of nitrogen and 
phosphoric acid in ground bone and tankage ; of available 
phosphoric acid in superphosphates, and of actual potash 
in the potash salts, and is a useful guide also in showing 
that the nitrogen, phosphoric acid and potash contained 
in these materials can be purchased in ton lots for the prices 
mentioned. The valuations of mixed fertilizers, obtained 
by the use of this schedule, are entirely commercial ; they 
are not intended to indicate even a possible agricultural value. 
This point needs to be emphasized, as many are inclined 
to interpret them as not only guides as to agricultural 
value, but as positive statements of such value. It can 
be said, however, that those who do so do not familiarize 
themselves with the discussions that usually accompany 
reports of analyses. The different trade values given for 
the nitrogen and phosphoric acid in the two grades of bone 
represent their value in the form of ground bone and of 
bone meal, products which are distinctly recognized in 
the market, and which are quoted at different prices. 
The coarser ground bone is lower in price than the finer 
bone meal. 

The accuracy of the schedule of values can be shown 
by comparing it with the actual prices paid for the con- 
stituents in the different materials, and such comparisons 
as have been made from year to year, by a number of the 
institutions exercising an analysis control, show that 
manufacturers and dealers are willing to sell to farmers 
at prices corresponding very closely with the schedule. 1 

A value is placed upon the insoluble phosphoric acid 

1 See Bulletins Connecticut and New Jersey Experiment 
Stations. 



184 Fertilizers 

in mixed fertilizers, not because all insoluble costs the 
price given, but because in mixtures it is assumed that the 
phosphoric acid is drawn from organic sources, which do 
cost, at least, the price given. 

There are arguments both in favor of and in oppo- 
sition to this method of comparing the commercial values 
of mixed fertilizers. The chief arguments in opposition 
may be stated as follows : 

First, that the prices of these materials vary, and 
hence in order to represent the actual commercial value 
at the time the sales are made, they should be changed 
as the markets change. 

Second, the valuations are misleading, because the 
farmer does not clearly understand their meaning, and 
is thus guided in his judgment of the usefulness or agri- 
cultural value of a fertilizer by the stated commercial 
value, as shown by this method, rather than by the kind, 
form and proportion of constituents that may be contained 
in it, and upon which its agricultural value should be 
based. 

Third, the chemical analysis does not show absolutely 
the sources of the materials, and thus it is difficult to place 
a true commercial value upon a mixture. This is espe- 
cially true of organic nitrogen, since because it is impos- 
sible to separate the amounts that may be derived from 
different materials, a uniform value is placed upon the 
total nitrogen found, whether it is derived from the best 
forms, as dried blood and dried meat, or whether derived 
from horn meal, ground leather or other low-grade forms 
of nitrogenous material. This encourages the use of low- 
grade products by unscrupulous manufacturers, to the real 
detriment of the trade as a whole. 

Fourth, that the commercial value so fixed militates 



Chemical Analyses of Fertilizers 185 

against the use of certain kinds of good materials, and 
in favor of certain kinds of poorer materials. That is, 
a valuation of 2 cents a pound for insoluble phosphoric 
acid in complete fertilizers, for example, is a direct encour- 
agement to include in the mixture a considerable propor- 
tion of the insoluble phosphoric acid from South Carolina, 
and other rock phosphates, the value of which is ignored 
in commercial transactions; while that price (2 cents) 
does not give a fair value to the phosphoric acid contained 
in bone, tankage and natural guanos, products in which 
the commercial value of the insoluble is recognized, — 
that is, mixtures which contain bone and tankage, and 
which furnish phosphoric acid largely in an insoluble form. 
The valuation fixed for this form is too low to fully repre- 
sent the commercial value of these goods. It is also said 
that the trade value for available phosphoric acid in the 
mixtures encourages the use of superphosphates from the 
rock phosphates, and discourages the use of superphos- 
phates from bone-black, bone-ash and dissolved bone, 
because the trade or commercial values represent the 
average cost of available phosphoric acid in the super- 
phosphates from all of these, while the latter materials, 
because of actual commercial conditions, cost more than 
the superphosphates from the former. 

The chief arguments in favor are : 

First, that it is not asserted that the system shows abso- 
lutely the commercial value of each brand at the time the 
sales are made, but the comparative commercial value. 

Second. They are not misleading. The commercial 
valuations are not intended to be a guide as to the agri- 
cultural value of a fertilizer. It is distinctly stated in the 
reports of analyses that the comparative values are 
purely commercial. 



186 Fertilizers 

Third. It is a system which more nearly approaches 
perfection than any other that has been devised, is edu- 
cative in its tendency, and is a safe guide, in the majority 
of instances, as to the charges made for mixing, handling 
and selling plant-food contained in the different brands. 
If the analysis is properly interpreted, as already indicated, 
it is the purchaser's fault if he buys poor forms of plant- 
food at a high price. It is certainly a safer guide than 
mere name of brand, and does not encourage the use of 
poor materials. 

Fourth. Any system of comparison of brands must 
leave a great deal to the judgment of the purchaser. 
He must interpret for himself whether he would rather 
that his phosphoric acid were derived from one source 
or another, whether he would prefer to pay a higher 
price for insoluble phosphoric acid in acid phosphate, 
and have the remainder soluble, than to pay the same 
or a greater price for the insoluble phosphoric acid in 
bone, and have the remainder of it in the reverted form. 
These conditions are again indicated by the analysis which 
accompanies the valuation ; the valuations are, therefore, 
not to be used in total disregard of the composition. If 
they are so used, it is not the fault of the system. That 
it militates against the use of high-priced superphos- 
phates, if they are no better than the lower-priced ones, 
is no argument against the system, but rather for it, since 
it tends toward a readjustment of the prices, a condition 
that must be met in all competitive trades. Furthermore, 
the valuation system has been effective in driving out ma- 
terials that are either fraudulent in their character or of 
very low-grade. It is impossible to obtain a high valua- 
tion on poor materials, and in the majority of cases de- 
pendence upon valuations alone would be a safe guide 



Chemical Analyses of Fertilizers 187 

as to the comparative agricultural value of brands of 
the same general composition. 

CALCULATION OF COMMERCIAL VALUES 

The following examples illustrate how commercial 
values of complete fertilizers and of ground bone are 
calculated. The mixed, or complete, fertilizer contains 
the three forms of nitrogen, three of phosphoric acid, 
and the two forms of potash. In the bone, it is assumed 
that 50 per cent of the meal is finer than 1-50 inch, and is, 
therefore, regarded as fine, and that 50 per cent is coarser 
than 1-50 inch, and is, therefore, regarded as coarse ; 
and it is also assumed that the proportions of the nitrogen 
and phosphoric acid in the fine and coarse is the same; 
also, that the analysis shows the bone to contain 4 per 
cent of nitrogen and 20 per cent of phosphoric acid : 

A Complete Fertilizer 



Nitrogen, as nitrates . . 
Nitrogen, as ammonia salts 
Nitrogen, as organic matter 
Phosphoric acid, soluble 
Phosphoric acid, reverted 
Phosphoric acid, insoluble 
Potash, as muriate 
Potash, as sulphate . . 



Estimated 

Value value per 

% or lbs. Lbs. per lb. ton of each 

per 100 per ton cts. constituent 

1 X 20 = 20 X 16.5 = $3.30 

1X20= 20 X 16.5 = 3.30 

1X20= 20 X 19.5 = 3.90 

8 X 20 = 160 X 4.5 = 7.20 

1 X 20 = 20 X 4.0 = .80 

1 X 20 = 20 X 2.0 = .40 

5 X 20 = 100 X 4.0 = 4.00 

5 X 20 = 100 X 5.0 = 5.00 



Total estimated value per ton $26.90 

The first column shows the percentage of the con- 
stituents contained, which, multiplied by 20, gives the 
pounds per ton in the second column, which, multiplied 



188 Fertilizers 

by the schedule prices a pound, gives the valuation per 
ton, as shown in the fourth column. 



Ground Bone 



4 5 6 



% or lbs. % of Value Estimated 

per fine- % or lbs. Lbs. per lb. value 

100 ness per 100 per ton cts. per ton 

f 4 X 50 = 2 in fine X 20 = 40 X 21.5 = $8.60 

Mitrogen . i 4x50= 2 in coarse X 20 = 40X17.5= 7.00 

Phosphoric I 20 X 50 = 10 in fine X 20 = 200 X 4.0 = 8.00 

acid . . ( 20 X 50 = 10 in coarse X 20 = 200 X 3.5 = 7.00 

Total estimated value a ton $30.60 



The first column of figures shows the per cent, or 
pounds per hundred, of the constituents, which is mul- 
tiplied by the percentage of fineness, which gives the 
percentage or pounds to the hundred of fine or coarse 
in the third column. The calculation is then finished as 
in the case of complete fertilizers. 

THE UNIFORMITY OF MANUFACTURED BRANDS 

Another point which consumers of fertilizers are in- 
terested in is the reliability of the various brands. That 
is, they desire to know whether a brand that shows good 
forms of nitrogen, of phosphoric acid, and of potash in 
one year may be depended upon to furnish approximately 
the same the following year, or whether the manufacturers 
change their formulas from year to year to conform to the 
relative cost of the different materials; that is, whether 
when nitrogen is relatively expensive and phosphoric 
acid is relatively cheap, they introduce a larger proportion 
of phosphoric acid and a smaller percentage of nitrogen ; 
whether when organic nitrogen is cheap and nitrate and 



Chemical Analyses of Fertilizers 189 

ammonia nitrogen are dear, they change the proportions 
of these to correspond with the difference in price, in order 
to retain the same selling price. 

This is an important point, since after a certain brand 
has been shown to be better suited than another to their 
conditions of soil, to change the formula, both in refer- 
ence to the character and proportions, may mean to the 
purchaser the difference between profit and loss. 

Evidence on this point can be obtained from the re- 
ports showing the results of the analyses of the different 
brands from year to year, and a careful study of these 
shows that genuine manufacturers of fertilizers — those 
who make it their sole business, rather than a side issue 
or an adjunct to another business — can be fully de- 
pended upon in this respect. They know that the farmer's 
interest is their interest, and that their sales will depend, 
other things being equal, upon the increased crop results 
that the farmer secures ; that the permanency and success 
of their business will depend upon the successful and 
profitable use of their product ; and that they cannot af- 
ford to and do not change their formulas from year to year, 
either in proportion or quality of constituents, to cor- 
respond with the changes in price of the materials. Their 
brands can be depended upon to furnish practically the 
same amount, kind and proportion of plant-food from 
year to year. 

The value of a fertilizer depends upon the kind, quality 
and form of plant-food, as shown by the analysis. Value 
does not depend upon who the manufacturer is, or what 
the statements may be concerning the usefulness of special 
manipulation, nor to any great extent upon special formu- 
las, unless the farmer has positive knowledge of the char- 
acter of his own conditions. Formulas derived both in 



190 Fertilizers 

kind and proportion from the same materials will do 
equally well under the same conditions. So far as the 
matter has been investigated, there is no specific virtue 
added by what is claimed to be the "blending" of the 
materials. 

In the whole matter of the purchase of fertilizers, no 
guide, however good, can take the place of intelligence on 
the part of the purchaser. This intelligence must be 
exercised in the selection of forms of plant-food, in the 
preparation of formulas, in the interpretation of guar- 
antees and of commercial values, and in the method of 
using the fertilizer. 



CHAPTER XI 

METHODS OF USE OF FERTILIZERS 

The primary object in the use of a commercial fertilizer 
is to receive a profit from the increase in the yield of crops 
from the land to which it is applied ; and this may be 
derived either from the immediate crop, or from the larger 
yield of a number of crops. That the greatest immediate 
or prospective profit may be gained, a wide knowledge of 
conditions which have either a direct or indirect bearing 
upon the result is essential. 

CONDITIONS WHICH MODIFY THE USEFULNESS OF 
FERTILIZERS 

In fact, the controlling conditions surrounding the 
matter are so numerous and so various that it is impossible, 
with our present knowledge, to lay down positive rules for 
our guidance. At best, only suggestions can be offered. 

We may possess a full knowledge of both the kind and 
form of existing fertilizer supplies, their cost and the action 
under known conditions of the constituents contained in 
each, as well as their maximum capability for increasing 
the crop, but together with this knowledge, it is essential 
that we should know how these facts and principles must 
be applied to each individual crop, soil and condition, and 
yet even with this, absolute certainty of profit is not 
guaranteed. A few of the more important conditions 

191 



192 Fertilizers 

which control the profitable use of fertilizers are, therefore, 
briefly discussed, in order to arrive at a better under- 
standing of the practical suggestions and concrete examples 
given in subsequent chapters. 

Derivation of soil a guide as to its possible deficiencies. 

The first consideration is the soil itself, and its influence. 
It is well known that a wide difference exists in soils, both 
in reference to their chemical character or composition, 
and to their physical properties, each having a direct 
influence in determining the effect of any specific applica- 
tion of fertilizers. These differences in soils are due to 
changes which were wrought in the surface of the earth 
during its formation, and which are continuing in a small 
way at the present time. It is believed that the original 
earth crust contained all the minerals now found in it, but 
that in the beginning they were distributed more uniformly 
throughout its mass, and that the soils as they exist at the 
present time, and as a result of the direct disintegration of 
the original rock, represent a very small area of the earth's 
surface. They are not now constant, but variable in their 
character. The various changes that have taken place 
during geologic time have resulted in the breaking up of 
the original rocks, a part having been separated mechani- 
cally and being represented by various sizes of particles, 
and a part rendered soluble. The fragments and the 
soluble portions thus separated have not been deposited 
again in the same proportions as they existed in the original 
rock, which has caused a very wide variation in the chemi- 
cal composition of the different soil deposits. The process 
and its results may be shown at the present time in the 
wearing away of rocks. The harder, sandy particles sep- 
arate mechanically, and because of the difference in the 



Methods of Use of Fertilizers 193 

size of the particles, the coarser are deposited as gravel or 
sand, in one place, and the finer particles are deposited in 
another, making the clay. The lime enters partly into so- 
lution and is deposited in another place, and so on, thus 
giving us sandy soils, clayey soils and limy soils, all differ- 
ing from each other in their amount and proportion of the 
essential fertilizing constituents, as well as in their physical 
qualities, — the sandy and gravelly making the poorest 
soils because the particles consist very largely of quartz, 
and the remainder being poor in phosphoric acid or potash. 
The clay soils are frequently rich in minerals containing 
potash, and poor in those containing lime and phosphoric 
acid ; and the limestone soils are poor in potash and rich 
in lime, and frequently in phosphates. In addition to these 
soils, there are those that are made up largely of vegetable 
matter, due to the accumulation of decaying growths. 
These are frequently rich in nitrogen and poor in all of the 
essential mineral constituents. 

Hence it is that in the use of a commercial fertilizer, 
at least for certain crops, a knowledge of the nature of soils 
in respect to the possible deficient element is important, 
in order that those which exist in abundance may not be 
added to, but that they may be supplemented by such an 
abundance of the deficient elements as to permit the ac- 
quirement by the crops of those necessary for a maximum 
growth. As a rule, potash is a very essential constituent 
of manures for sandy soils, not only because all crops 
require potash, but because they require it in relatively 
large amounts, and because in sandy soils it is liable to 
exist in minimum amounts. Potash fertilization, therefore, 
is especially useful on sandy soils. On the other hand, in 
clay soils, which, as a rule, contain a very considerable 
proportion of potash as compared with sandy soils, the 



194 Fertilizers 

deficient element may be either phosphoric acid or lime; 
and if these are supplied in abundance, the plant will be 
able to secure the necessary potash. In a limy soil, the 
lime and phosphoric acid, and perhaps the potash, may be 
in sufficient abundance to cause a normal growth of plant, 
yet the nitrogen may be so deficient as to prevent a normal 
growth. 

Physical imperfections of sandy soils. 

If it were possible distinctly to classify soils in respect 
to their lack of one or more of the essential constituents, 
it would be an easy matter to formulate rules for our 
guidance in the fertilization of these soils ; but such is not 
the case. Even sandy soils vary widely in their chemical 
composition, as well as in their mechanical or physical 
properties, and certain of them possess such a physical 
character as to make it impossible to grow maximum crops 
even though the essential elements are all supplied in 
sufficient abundance. The constituent particles are too 
coarse, and thus make the soils so open and porous that 
they too freely admit the air, water and warmth, and thus 
results a very rapid drying and heating of the soil, with a 
premature ripening and burning of the crops. The phos- 
phates or the potash compounds applied are not readily 
fixed, and suffer an immediate loss as soon as rain falls in 
such amounts as to cause a leaching from them. 

Physical imperfections of clay soils. 

In clay soils, the physical conditions are quite the reverse. 
All clay soils do not have the same general composition, 
and they differ widely in their physical qualities. Certain 
of them possess a reasonably good texture, and permit the 
absorption of the food applied, as well as its gradual dis- 



Methods of Use of Fertilizers 195 

tribution throughout the mass by the percolation of the 
water through them ; while certain others are so compact, 
owing to the finely divided particles, that even though they 
were abundantly supplied with all of the necessary mineral 
constituents, profitable crops could not be grown because 
the roots could not readily penetrate, and because the 
water falling upon the land would not readily pass through, 
but remain upon the surface. 

In the case of soils with an abundance of lime, physical 
qualities also exercise a very considerable influence, even 
though there is a sufficient supply of all of the fertility 
elements. Certain of them are too cold, others are too dry, 
and the mechanical condition is such as to prevent the 
proper and uniform growth of plants. It must be remem- 
bered, then, that only general rules apply in the use of 
fertilizers upon soils of the different classes, and that they 
are modified by both the chemical composition and the 
mechanical condition of the soils. The best use of a fer- 
tilizer — that is, the greatest proportionate return of 
plant-food in the crop, all things considered — is obtained 
from its application upon soils that possess "condition," 
or that are well cultivated or managed. Full returns can- 
not be expected when they are applied upon soils that are 
too wet or too dry, too porous or too compact, or too coarse 
or too fine. It is important that even the best soils should 
be properly prepared, and it is infinitely more important 
that those which possess poor mechanical condition should 
be improved in this respect, before large expenditures are 
made for fertilizers. 

The influence of previous treatment and cropping. 

In the next place, the previous treatment and cropping 
of soils should guide in the use of fertilizers, since soils of 



196 Fertilizers 

the same natural character, located equally well, will not 
always show the same results from the application of 
fertilizers, because in the one case the cropping has been 
such as to result in the rapid exhaustion of one, rather than 
the three specific fertilizer elements ; while in the other, the 
cropping may have been quite as severe, but has been help- 
ful because judicious rotations have been used and improved 
methods practiced. It may be that in the one case, there 
may have been a continuous cropping of wheat, for exam- 
ple, and only the grain sold from the farm, in which case 
there would be a much more rapid exhaustion of the nitro- 
gen and phosphoric acid than of the potash ; and if this 
continuous wheat-cropping has been continued for a long 
time, an application of the phosphates only may result in 
quite as large an increase in crop as if both phosphates and 
potash salts were applied, because the potash exhaustion 
has been less rapid than that of the phosphoric acid, and 
the addition of potash would simply add to the probably 
abundant quantities already there. On the other hand, 
if the cropping has been timothy hay, the removal of the 
potash would have been greatly in excess of the phosphoric 
acid, and consequently a fertilization with a greater propor- 
tion of potash, or even this element alone, of the minerals, 
may result in quite as large returns as if the fertilization 
had consisted of both phosphoric acid and potash. In 
fact, if the land had been cropped continuously with 
tobacco, cotton, potatoes or other crop, there is likely to 
be a much larger removal proportionately of some one 
element, rather than proportionate amounts of all. This 
practice results in a disproportionate removal of the con- 
stituents, and in order to bring the land back to its capac- 
ity for maximum production, or to equalize matters in this 
respect, it is necessary to add to the soil the constituents 



Methods of Use of Fertilizers 197 

removed in amounts in excess of the others. On the other 
hand, the cropping may have been such as to be fully as 
exhaustive in the sense that the total quantity of constitu- 
ents removed is quite as great, though since they are 
removed in more uniform proportions, the period of prof- 
itable cropping is extended, and the fertility needed in- 
cludes all the essential elements, rather than one or two. 
That is, the grain, hay and potatoes may have been grown 
in rotation, each removing one or the other in greater 
proportion, but because they differ with each crop, no 
one is exhausted before the other; and thus when the 
land reaches the time when it would no longer profitably 
grow those crops, an application then of all of the con- 
stituent elements would result in a greater and more 
profitable increase in crop than if the fertilizer contained 
one constituent only. The previous treatment and crop- 
ping of soils, therefore, is an important guide in determining 
the most economical method of fertilization. 

Furthermore, in this matter of cropping as a guide to 
possible need of fertilization, it must be remembered that 
a continuous one-crop practice is more productive of total 
loss of constituents than a practice which includes such 
renovating crops as clover, or one which permits of a more 
constant occupation of the land, since in the former, the 
introduction of clover reduces the need for nitrogen fer- 
tilization, and in the latter, the vegetable matter is not so 
rapidly used up, and the loss of mineral constituents by 
mechanical and other means is very much reduced, because 
of the constant occupation of the land. 

The influence of character of crop. 

The financial result from the application of fertilizers 
is also influenced in a very large degree by the character 



198 Fertilizers 

of the crop itself, whether the value of an increase in crop 
as great as can be expected from a definite application is 
high or low ; and on this basis, crops may be classified 
into two general groups : first, those which possess a high 
fertility, and which, as a rule, possess a relatively low com- 
mercial value ; and second, those which possess a low fer- 
tility value and a relatively high commercial value. In the 
first class are included the cereal and forage crops, as corn, 
oats, wheat, hay, buckwheat, cotton and tobacco, and in 
the second are included the various vegetable and fruit 
crops. This classification, and its importance, may be 
illustrated by the following examples : 

A ton of wheat, at $1 a bushel, will bring $33.33. Its 
sale removes from the farm 38 pounds of nitrogen, 19 of 
phosphoric acid and 13 of potash. At prevailing prices 
for these constituents, it would cost $6.50 to return them 
to the farm. 

A ton of asparagus shoots, at 10 cents a pound bunch, 
will bring $200. Its sale removes from the farm 6 pounds 
of nitrogen, 2 of phosphoric acid and 6 of potash, which 
could be returned for but little more than $1. 

A ton of timothy hay will bring $14. Its sale removes 
from the farm 18 pounds of nitrogen, 7 of phosphoric 
acid and 28 of potash, amounts that would cost $4. 

A ton of apples will bring in an ordinary season $20. 
It removes less than 3 pounds of nitrogen, 1 of phosphoric 
acid and 4 of potash, which would cost less than 60 cents 
to return to the land. 

It is thus shown that crops like wheat and hay possess 
a relatively low commercial value, and yet carry away, 
when sold, a very considerable amount of the fertilizing 
constituents, while vegetables and fruits, as illustrated by 
the asparagus and the apples, have a high commercial or 



Methods of Use of Fertilizers 199 

market value, and carry away but minimum amounts of 
the fertilizing constituents. This distinctive character of 
crops, while not an absolute guide as to the profits that may 
be obtained from the use of fertilizers, — since the cost of 
production varies widely for each class, — is instructive 
in showing that those of a low commercial value are more 
exhaustive than the other class, or those of a high market 
value, and is certainly suggestive, pointing out the neces- 
sity for judgment in the application of fertilizers that shall 
be made in the case of crops of the different groups. 

The kind of farming, whether "extensive or intensive." 

Another very important consideration, and one which 
exercises an influence, is whether the farming engaged in 
is "extensive" in its character, or "intensive"; whether 
the purpose or idea is simply to supplement the stores of 
plant-food in the soil, or whether the object is to insure an 
abundance of all forms of constituents under all reasonable 
conditions, in order that a maximum production may be 
secured. 



PLANTS VARY IN THEIR POWER OF ACQUIRING FOOD 

In the next place, the character or feeding capacity of 
the plant and its season of growth should be considered, 
that systematic methods may be adopted, and thus not 
only that waste of fertilizing materials may be avoided, 
but that the applications may be made at such times and 
in such amounts as will, other things being equal, promote 
the greatest increase per unit of applied food. 

While each plant possesses individual characteristics 
which distinguish it from all others, for our purpose they 
may again be classified into general groups which possess 



200 Fertilizers 

somewhat similar characteristics, particularly as to their 
method and time of growth and their capacity for acquir- 
ing food from soil sources. 

Characteristics of the cereal group. 

The cereals possess distinct characteristics of growth. 
The roots branch just below the surface, and each shoot 
produces feeding roots, which distribute themeslves in 
every direction, and thus absorb food from the lower layers 
of the soil as the plant grows older. Because of their wide 
root system, and because of the character of their feeding 
rootlets, they are able readily to acquire food from the 
insoluble phosphates and potash compounds of the soil, 
though they are unable to feed to any extent upon the 
insoluble nitrogen. Furthermore, inasmuch as the most 
rapid development of many of these crops takes place 
early in the summer, before the conditions are favorable 
for the rapid changing of organic nitrogen into nitrates, 
they are, with the exception of Indian corn (maize), 
specifically benefited by early applications of nitrogen in 
the form of nitrate. The corn, on the other hand, which 
makes its most rapid growth after the other cereals are 
harvested, — in July or August, — when the conditions 
are particularly favorable for the development of nitrates, 
do not usually require as large proportions of nitrogen as 
of the mineral constituents, particularly the phosphates. 
That is, wheat, rye, oats and barley are specifically 
benefited by the early application of quickly available 
nitrogen. 

Characteristics of grasses and clovers. 

Forage crops, including both the grasses and clovers, 
constitute another group, in so far as their use is concerned, 



Methods of Use of Fertilizers 201 

though possessing marked distinguishing characteristics. 
Of the grasses, nearly all species are perennial, though their 
length of life depends upon the method of cropping and 
upon the character of the soil. They send their fibrous 
roots into the surface soil in the same manner as the cereals, 
though they differ from them in forming a set of buds 
which become active in the late summer and develop new 
roots and shoots. They resemble the cereals in their 
power of acquiring mineral food, and are even more bene- 
fited by the application of nitrogen, since the chief object 
in their use is to obtain the nitrogenous substances con- 
tained in leaf and stem in the form of pasture, forage or 
hay, rather than the matured grain. Hence, nitrogen, 
which promotes this form of growth, is an important 
constituent, and under any conditions there should be a 
liberal supply provided. 

The clovers, on the other hand, are not perennial, with 
the partial exception of "white" or "Dutch" clover, and 
with this exception they all possess a taproot, which pene- 
trates downward, and as it descends, throws out fibrous 
roots into the various layers of soil. They are capable 
of readily acquiring their mineral food, both because 
of their large root systems and because of the charac- 
ter of the roots. They, however, differ in one very 
important particular from the cereals and grasses, 
in that under proper conditions, as already pointed 
out (p. 129), they are capable of acquiring their ni- 
trogen from the air. Thus with liberal dressing of 
only phosphoric acid and potash, maximum crops may 
be secured. They are "nitrogen gatherers," and the 
tendency of their growth is to improve the soil for the 
nitrogen consumers, or for those that obtain their ni- 
trogen only from soil sources. 



202 Fertilizers 

Root crops. 

Another class of plants, differing from those already 
described, includes the root crops, as beets, mangels, 
turnips and carrots. These plants cannot make ready 
use of the insoluble mineral constituents of the soil. 
Hence, in order to insure full crops, they must be liberally 
supplied with available food. Of the three classes of fer- 
tilizing constituents, the phosphates are especially useful 
for turnips, while the slower-growing beets and carrots 
require that the nitrogen shall be in quickly available 
forms. The proper fertilization of sugar beets, for exam- 
ple, is of great importance, since not only is the yield 
affected by fertilization, but the quality of the beet for the 
production of sugar. 

White potatoes and sweet potatoes, the one a tuber, the 
other an enlarged root, constitute another class which does 
not possess strong foraging powers. They require their 
food in soluble and available forms, and with suitable soils 
potash is the ingredient that is especially useful in the 
manures applied. 

Market-garden crops. 

Another group of crops is distinguished as a class, not so 
much because of their peculiar habits of growth as because 
of the objects of their growth, though this latter fact has a 
very important bearing upon economical methods of fer- 
tilization. This class includes what are called "market- 
garden crops," as lettuce, beets, asparagus, celery, turnips, 
cucumbers, melons, sweet corn, beans, peas, radishes and 
various others. The particular object in raising these is to 
secure rapidity in growth, and thus to insure high quality, 
which is measured by the element of succulence. In order 



PLATE IX. — Lima Beans and Potatoes. 




Fig. 17. — Ninety-ache Field of Lima Beans for Canning, Free- 
hold, New Jersey. A Good Example of a Field Truck Crop. 







Fig. 19. — One Ton of High-grade Fertilizer Used upon Early 
Potatoes is the Common Practice among Growers in New Jersey. 



Methods of Use of Fertilizers 203 

that this may be accomplished, they must be supplied 
with an abundance of available plant-food, and since 
nitrogen is the one element which more than any other 
encourages and stimulates leaf and stem growth, its use is 
especially beneficial to all of these crops. They must not 
lack for this element in any period of their growth, though, 
of course, a sufficiency of minerals must be supplied in 
order that the nitrogen may be properly utilized. Because 
of their high commercial value, the quantity of plant-food 
applied may be greatly in excess of that for any other of 
the groups, and profits, as a rule, are measured by this 
excess rather than by the proportion of the elements. 

Fruit crops. 

Another distinct class of crops, though differing materi- 
ally in their individual characteristics, as well as in their 
time and period of growth, are the fruits. These differ 
from most other crops, in that a longer season of prepara- 
tion is required, in which the growth may be so directed 
as to prepare the plant or tree for the proper development 
of a different kind of product, namely, fruit, as distinct 
from grain or seed in the cereals, or succulence in the 
vegetable crops. The fruit differs in its characteristics 
from the ordinary farm crops, in that its growth and de- 
velopment require a little different treatment, since it is 
necessary that there shall be a constant transfer of food 
from the tree to the fruit throughout the entire growing 
season. The growth of each succeeding year of tree and 
fruit is dependent, not altogether upon the food acquired 
during the year, but as well upon that acquired in the 
previous year, and which has been stored up in bud and 
branches. A knowledge of the habits of growth, the period 
of growth and the object of the growth of this class is, 



204 Fertilizers 

therefore, useful as a guide to the economical supply of the 
essential elements of growth. These crops must be pro- 
vided with food that will encourage a slow and continuous 
rather than a quick growth and development. 

SYSTEMS OF FERTILIZING SUGGESTED 

A careful review of the foregoing facts furnishes abun- 
dant evidence of the impracticability of attempts to give 
information concerning the use of fertilizers that will apply 
equally well under all of the conditions of farming that 
may occur. Nevertheless, there have been a number of 
methods or systems of fertilization suggested, each of 
which possesses one or more points of advantage. 

A system based upon the specific influence of a single element. 

The one which has perhaps received the most attention, 
doubtless largely because one of the first presented, and in 
a very attractive manner, is the system advocated by the 
celebrated French scientist, George Ville. This system, 
while not to be depended upon absolutely, suggests lines 
of practice which, under proper restrictions may be of 
very great service. In brief, this method assumes that 
plants may be, so far as their fertilization is concerned, 
divided into three distinct groups. One group is specifi- 
cally benefited by nitrogenous fertilization, the second by 
phosphatic, and the third by potassic. That is, in each 
class or group, one element more than any other rules or 
dominates the growth of that group, and hence each par- 
ticular element should be applied in excess to the class of 
plants for which it is a dominant. In this system it is 
asserted that nitrogen is the dominant ingredient for wheat, 
rye, oats, barley, meadow grass and beet crops. Phos- 



Methods of Use of Fertilizers 205 

phoric acid is the dominant fertilizer ingredient for tur- 
nips, Swedes, Indian corn (maize), sorghum and sugar 
cane; and potash is the dominant or ruling element for 
peas, beans, clover, vetches, flax and potatoes. It must 
not be understood that this system advocates only single 
elements, for the others are quite as important up to a 
certain point, beyond which they do not exercise a con- 
trolling influence in the manures for the crops of the three 
classes. This special or dominating element is used in 
greater proportion than the others, and if soils are in a high 
state of cultivation, or have been manured with natural 
products, as stable manure, they may be used singly to 
force a maximum growth of the crop. Thus, a specific 
fertilization is arranged for the various rotations, the crop 
receiving that which is the most useful. There is no doubt 
that there is a good scientific basis for this system, and that 
it will work well, particularly where there is a reasonable 
abundance of all of the plant-food constituents, and where 
the mechanical and physical qualities of soil are good, 
though its best use is in "intensive" systems of practice. 
It cannot be depended upon to give good results where the 
land is naturally poor, or run down, and where the physical 
character also needs improvement. 

A system based upon the necessity of an abundant supply of 
the minerals. (Wagner System.) 

Another system which has been urged, notably by Ger- 
man scientists, is based upon the fact that the mineral 
constituents, phosphoric acid and potash, form fixed com- 
pounds in the soil, and are, therefore, not likely to be 
leached out, provided the land is continuously cropped. 
They remain in the soil until used by growing plants, while 
the nitrogen, on the other hand, since it forms no fixed 



206 Fertilizers 

compounds and is perfectly soluble when in a form useful 
to plants, is liable to loss from leaching. Furthermore, 
the mineral elements are relatively cheap, while the nitro- 
gen is relatively expensive, and thus the economical use 
of this expensive element, nitrogen, is dependent to a 
large degree upon the abundance of the mineral elements 
in the soil. It is, therefore, advocated that for all crops 
and for all soils that are in a good state of cultivation, a 
reasonable excess of phosphoric acid and potash shall be 
applied, sufficient to more than satisfy the maximum needs 
of any crop, and that the nitrogen be applied in active 
forms, as nitrate or ammonia, and in such quantities and at 
such times as will insure the minimum loss of the element 
and the maximum development of the plant. The supply 
of the mineral elements may be drawn from the cheaper 
materials, as ground bone, tankage, ground phosphates 
and iron phosphates, as their tendency is to improve in 
character ; potash may come from the crude salts. Nitro- 
gen should be applied chiefly as nitrate of soda, because in 
this form it is immediately useful, and thus may be applied 
in fractional amounts, and at such times as to best meet 
the needs of the plant at its different stages of growth, with 
a reasonable certainty of a maximum use by the plants. 
Thus no unknown conditions of availability are involved, 
and when the nitrogen is so applied, the danger of loss by 
leaching, which would exist if it were all applied at one 
time, is obviated. 

This method also possesses many advantages, particu- 
larly where the "intensive" system is practiced, though 
it is also useful in quickly building up wornout soils, or 
those naturally poor, because in any case these must be 
provided with liberal supplies of the minerals, and when 
these only are applied, the immediate outlay is far less 



Methods of Use of Fertilizers 207 

than if the expensive element, nitrogen, were included ; and 
a greater economy in the use of nitrogen is accomplished if 
it is added in small amounts when required. Besides, in 
the improvement of soils, the liberal application of the min- 
erals is conducive to an abundant growth of the legumes, 
which are able to acquire their nitrogen from the air, thus 
reducing to some extent the outlay for this expensive ele- 
ment. This system is strongly recommended where cheap 
phosphatic and potassic materials are readily accessible, as 
is the case in those countries where it is successfully used. 

A system based on the needs of the plants for the different 
elements as shown by chemical analysis. 

Another system of fertilization is based upon the theory 
that the different plants should be provided with the essen- 
tial elements in the proportions in which they exist in the 
plants, as shown by chemical analysis. Different formulas 
are, therefore, recommended for each crop, the constituents 
of which are so proportioned as to meet its full needs. 
This method, if care is taken to supply an abundance of 
all the necessary constituents, may result in a complete 
though perhaps not an economical feeding of the plant, 
since it assumes that a plant which contains a larger amount 
of one constituent than of another requires more of that 
constituent in the fertilizer than of the others. It does 
not take into consideration the fact that the plant which 
contains a larger amount of one element than another 
may possess a greater power of acquiring it than one which 
contains a smaller amount. 

Neither does this system take into consideration, as al- 
ready pointed out (p. 199), that the period or time of growth 
of the plant also exercises a considerable influence in indi- 
cating the capability of the plant to acquire its necessary 



208 Fertilizers 

food from the stores of the soil, as may be illustrated by 
wheat and Indian corn, which both contain a relatively high 
content of nitrogen. Under good conditions of soil, wheat 
is specifically benefited by heavy dressings of quickly avail- 
able nitrogen. Corn is not, and one reason is, that they 
possess different powers of acquiring food, due, to a con- 
siderable extent, to the difference in their time of growth, 
as well as to the period or time of their most rapid growth. 
This method may, however, be applied with very great 
advantage in greenhouse work, or in growing market- 
garden crops, where the amounts in the soil are not re- 
garded as of importance, and excessive amounts of all are 
added. The system has been elaborated to a great degree 
of nicety for the growing of greenhouse crops, flowers and 
foliage plants, so much so that now artificial manure car- 
tridges are prepared, which contain the amounts and kinds 
of food shown by the analysis of the different plants to be 
needed for their growth and full development. "The 
manure has the form of a fine powder, enclosed within a 
metallic wrapper, and firmly compressed into the shape of 
a cartouche or capsule, cylindrical in form, about three- 
fourths inch across and one-half inch in depth. It is 
simply thrust into the soil of the pot to a depth of one-half 
or one inch, and allowed to remain. After a time it is 
found that the fertilizer gradually disappears, and at 
length nothing is left but the little pill-box-like wrapper, 
which originally contained the mixed fertilizing powder." 1 

A system in which the fertilizer is applied to the "money 
crop" in the rotation. 
Another system is also recommended, which is well 
adapted for "extensive" farming, where the majority of 

1 "The Gardener's Chronicle," London, England. 



Methods of Use of Fertilizers 209 

crops which are grown in rotation possess a high fertility 
value and a low commercial value, and where one crop is 
regarded as the chief "money-maker." The system de- 
mands that to this crop shall be applied such an abundance 
of plant-food as to insure a continuous feeding, and a con- 
sequent maximum production, even though adverse condi- 
tions intervene. Thus by a liberal supply of food, a money 
crop is secured which is as large as climate and seasonal 
conditions will permit, though which does not require all 
of the food applied. Hence the residue may be depended 
upon to fully nourish the remaining crops in the rotation, 
or at least the immediately succeeding ones, thus saving 
direct outlay for them. This system may be illustrated 
as follows : 

On soils in good physical condition, and naturally well 
adapted for growing potatoes, this crop is selected as the 
"money-maker" in the rotation, which consists of corn, 
potatoes, wheat, clover and hay. The potato crop is 
fertilized so liberally, say with 1500 pounds to the acre, 
of a fertilizer containing — 

Nitrogen 4% 

Phosphoric acid 8% 

Potash 10% 

as to insure its maximum growth under average conditions. 
The removal of a large crop would still leave a large residue 
of plant-food, which would provide the following wheat 
crop with at least all of the mineral elements necessary to 
produce a maximum crop. If the wheat does not show 
vigorous growth in the spring, it is lightly top-dressed with 
nitrate of soda, which not only feeds it directly with 
nitrogen, but strengthens and invigorates the plant, en- 
abling it to secure the minerals needed. The removal of a 



210 Fertilizers 

large crop still leaves an unused residue, upon which the 
clover crop following is also able to make a maximum 
growth, and thus three crops are fertilized with the one 
application. The hay is either fertilized with both the 
minerals and nitrogen, or lightly top-dressed with nitrogen 
early in the spring. The yard manure, accumulated from 
the residue of straw, hay and corn, is applied to the corn, 
which, being a gross feeder, is able to obtain from this an 
abundance. Thus, by the heavy application of fertilizer 
upon the "money crop," all the crops in the rotation are 
benefited. 

This method possesses many valuable features, and is, 
perhaps, quite as well adapted as any other for this system 
of farm practice. 

An irrational system. 

The most expensive and irrational system of all, and 
one more commonly practiced than any other in general 
farming, may be termed the "hit or miss" system; if a 
"hit" is made, there is a profit, if a "miss," the loss is 
trifling. In this system, no special thought is given to the 
character of the crop or its needs. If the farmer can 
afford it, he purchases a fertilizer, without regard to its 
composition, and applies it in very small amounts. If it 
happens to contain that element which is particularly 
needed for the plant to which it is applied, a profit is 
secured. In too many cases, however, the constituents 
added are already in abundance in the soil, or so little of 
the fertilizer is used as to preclude any profit. 

SUMMARY 

With the exception of this last system, there are good 
features in all of these suggested methods of use, and it 



Methods of Use of Fertilizers 211 

rests with the farmer to select the best points from each, 
or rather to use the suggestions in each which are in his 
judgment more applicable to his conditions. They are 
all based upon underlying principles, and pre-suppose a 
knowledge of them on the part of the farmer. They are, 
at best, but guides or sign-posts pointing toward better 
methods in the use of fertilizers, rather than absolute rules 
to be followed blindly. 

It may be pointed out that these systems do not take 
into consideration the character of the soil. Vast differ- 
ences exist between soils, not only in their natural content 
of plant-food but also in their physical and mechanical 
character, which is so important in the retention and libera- 
tion of plant-food. Nor do these systems give apprecia- 
tion to rational farm practices such as green-manuring 
and liming which have such a material effect upon the soil 
stores of plant-food. In view of these facts the good 
points of the various systems should not only be utilized 
but they should also be fortified by experimentation. A 
more complete discussion of simple experiments for this 
purpose may be found in the following chapter. 

The suggestions here and in subsequent chapters, in 
reference to the use of fertilizers, are formulated from the 
best information obtainable by the writer, and mainly from 
two sources : First, the results of experimental inquiry, 
and, second, the results of the observation and experience 
of practical men. In no case can absolute rules be laid 
down. Farmers may safely rely on the well-established 
principles, but each must remember that the use of the 
principles must be modified according to his own condi- 
tions. 



CHAPTER XII 

FERTILIZERS FOR CEREALS AND GRASSES 

It has already been pointed out (p. 198) that these 
crops are classed as possessing a relatively low com- 
mercial value and a relatively high fertility value, and 
that, from a practical standpoint, in any fertilization of 
them a possible profitable return should be borne in mind. 
This is, of course, necessary in all cases, but is particularly 
necessary where an increased yield, as great as can be 
expected from an application of proper fertilizing materials, 
cannot possibly result in an extraordinary profit, a result 
quite possible with certain crops of the opposite class. 
The possible increase in yield, also, is dependent on the 
conditions of soil and season, and if these latter are such 
as to forbid a maximum increased yield, the immediate 
profits from the application are reduced considerably. 

It has been shown, also, by careful experiments that, 
on the average, at least one-third of the nitrogen applied 
to these crops, although contained in the best forms, is not 
secured in the crop, even under the most favorable condi- 
tions ; that is, in any case certain amounts are lost through 
drainage, the growth of weeds and denitrification ; and, 
further, that the minerals must exist in the soil, or must be 
supplied in sufficient excess, otherwise the utilization of 
the nitrogen by the plant is still further reduced. The 
expense of fertilizer to the unit of increase in these crops 

212 



Fertilizers for Cereals and Grasses 213 

is, therefore, relatively greater, even under the best con- 
ditions of its use. A bushel of wheat, with its accom- 
panying straw, will contain, for example : 

Nitrogen If lbs. 

Phosphoric acid f lb. 

Potash If lbs. 

It will be observed that the amounts of fertilizer ingre- 
dients contained in the crop are such that if the seasonal 




Fig. 14. — Grain Drill with Fertilizer Sower. 

The grain drill with fertilizer sower has justly come into very general 
use. It sows the seed and evenly distributes fertilizer, at the same time 
covering both with sufficient soil. 



conditions are perfect, so that the maximum of the 
amounts applied are recovered in the crop, the cost of 
fertilizers to a bushel of increase is still relatively high, 
thus showing that great care must be exercised in order 
that a direct and immediate profit may be secured. 
Nevertheless, since the cost of preparing the land and of 
harvesting the crop is but slightly greater for a large crop 
than for a small one, the larger returns for the labor very 



214 Fertilizers 

frequently pay well for the application of the material, 
even though the margin of money profit is small. In 
crops of this sort therefore, and especially when grown 
on the "extensive" plan, an important point to be 
determined is whether the land is deficient in all of 
the constituents for grain and hay growing, or whether 
only one or two are lacking, in order that in the appli- 
cations made, only those constituents are supplied that 
are necessary, and adding to an excess already present 
is thus avoided, with a consequent saving in the cost 
of the fertilizer. 

EXPERIMENTS TO DETERMINE THE LACKING ELEMENT 

The lacking element cannot be fully determined, except 
by direct experiments by the farmer himself. That is, 
no general principle can be depended on as an absolute 
guide. He should learn whether his soil is deficient in 
any of the elements, and, if so, which ones should be 
applied to the different crops in his rotation. A careful 
study along this line, too, will show whether it is fertiliza- 
tion that is required to meet seeming deficiencies, for it fre- 
quently happens that the needs of the soil are not so much 
for added plant-food as for better management of the 
soil in other respects, in order that natural supplies may 
be made more available. 

It may seem, at first glance, that experimenting should 
be left to the experiment stations, and that farmers 
should be advised by them of the needs of their soils in 
respect to plant-food. This is partly true, but the proper 
function of experiment stations is to establish principles, 
the application of which must be left, in large part at 
least, to the intelligence of those who are to utilize them. 



Fertilizers for Cereals and Grasses 215 

The farmer must study his own conditions. Scientific 
inquiry has established the facts that soils differ in their 
content of the different plant-food elements, and that 
those of practically the same chemical composition differ 
in respect to their physical qualities, which conditions 
exercise an important influence upon the availability of 
the constituents. 

This experimenting may also seem to be a trouble- 
some operation, yet, if thoughtfully managed, it will 
mean but little extra labor, and the resulting gain may be 
far in excess of the cost of the work. For example, if it is 
shown that fertilization under certain conditions is not 
needed, and therefore not profitable, it saves possible 
outlay at once ; if it shows that the application of certain 
of the constituents is a profitable practice, it enables the 
adoption of a systematic scheme of fertilization. 

A scheme for plot experiments. 

The following simple scheme of plot experimenting 
has been suggested, and it admits of determining many 
of the points involved. This scheme includes ten plots, 
in which three are to be cropped without manure, as 
check plots, in order to show the productive capacity of 
the unmanured land. The plots may vary in size, though 
it is desirable that they should contain at least one-twen- 
tieth of an acre, and that they should be long and narrow 
(one rod wide and eight rods long is a size), in order to 
include as many inequalities of the soil as possible ; though 
in any case land as uniform as possible in physical and 
chemical qualities, and fairly representative, should be 
selected. The following plan permits of a study of the 
effect of the application of individual constituents, and 
of their various combinations. If desired, in order to sim- 



216 Fertilizers 

plify the work in the beginning, only the first four plots 
need be taken. This will reduce the labor, and, at the 
same time, permit a study of the soil's deficiencies in 
respect to single elements of plant-food, and the relative 
needs of the different crops for the various constituents. 

The rate of application to the acre is greater than would 
naturally obtain in practice, in order to facilitate the dis- 
tribution of the fertilizer, to furnish a sufficient abundance 
of the constituent, and to provide against unfavorable 
conditions. 

Preferably, the application should be made broadcast, 
and before planting, though for cultivable crops it may be 
applied later and harrowed into the soil. 

It will be observed that the amounts of fertilizer are 
one pound to the square rod, or multiple thereof. Thus, 
in order to insure an equal distribution over the entire 
area, it may be roughly divided into plots of a square rod, 
and the required material for each rod applied separately. 
Careful weights should be made of the yields of the dif- 
ferent plots, as a basis of comparison. The same ferti- 
lizers should be used on the different crops of the rotations, 
and as interest is increased in the work, different forms 
and amounts of the various constituents may be intro- 
duced. 

Results that may be attained. 

If it is found that for a certain crop only one of the 
applied constituents profitably increases the yield, then 
that should be used until the need of the others is appar- 
ent. If two are needed to accomplish the results, use 
two, and so on; though in the long run, or as the prac- 
tice approaches the "intensive" system, all will doubt- 
less be required. In "extensive" farming this is a very 



Fertilizers for Cereals and Grasses 217 

Plan op Experiment — Size of Plots, -£$ op an Acre 

132' 



Plot I. 

1— ' 

OS 

fc5|W 


Check — No fertilizer. 


Plot II. 


Nitrate of soda. 


8 pounds. 


Plot III. 


Acid phosphate. 


16 pounds. 


Plot IV. 


Muriate of potash. 


8 pounds. 


Plot V. 


Check — No fertilizer. 


Plot VI. 


Nitrate of soda. 
Acid phosphate. 


8 pounds. 
16 pounds. 


Plot VII. 


Nitrate of soda. 
Muriate of potash. 


8 pounds. 
8 pounds. 


Plot VIII 


Acid phosphate. 
Muriate of potash. 


16 pounds. 
8 pounds. 


Plot IX. 


Nitrate of soda. 
Acid phosphate. 
Muriate of potash. 


8 pounds. 

16 pounds. 

8 pounds. 


Plot X. 


Check — No fertilizer. 



218 Fertilizers 

desirable line of experimentation, and can be carried out 
by individual farmers. It is useful not only in showing 
the deficiencies of the soil for the various crops, but is 
educative in its character, as it familiarizes the farmer with 
the materials that are used in making fertilizers, and 
encourages exact methods of work. Since, as already 
stated, the need very frequently is not so much for added 
fertility as it is for better preparation and cultivation of 
the soil, or for amendments such as lime, it would be a 
desirable practice to include in the number of plots here 
indicated one or two in which the cultivation of the soil 
was made more perfect, in order to determine whether 
the need is for more fertility elements or whether it is for 
better tillage, the effect of which is to render more of the 
soil constituents available to the plant. One or two to 
which lime is added may be advisable, in order to deter- 
mine whether this substance is needed either to correct 
acidity or to make available otherwise unusable com- 
pounds. This method, while particularly desirable where 
"extensive" methods of practice prevail, is of less im-. 
portance where the aim is to grow maximum crops, in 
which case both the crop and its rotation are to be con- 
sidered, and the needs of the plant rather than the de- 
ficiencies of the soil require first attention. 

The results of experiments which have been conducted 
with great care in a number of states show that where 
"extensive" methods are practiced certain elements 
need not be added in the fertilizers ; that is, that the soil 
contains such an abundance of them that the plant is 
able to obtain a full supply, at least, for a long time. For 
example, it has been shown that on the chief sugar-pro- 
ducing soils of Louisiana and Mississippi, and the cotton 
soils of Georgia and Texas, the addition of potash has been 



Fertilizers for Cereals and Grasses 219 

of less importance in the past than the other elements, and 
it frequently does not need to be included in the fertilizer, 
while phosphoric acid is always needed. 

The results of field experiments on this plan in New Jer- 
sey, on reasonably good, loamy soils, indicate that phos- 
phoric acid and potash are of much more importance in 
fertilizers for corn than nitrogen, whereas upon sandy 
soils, nitrogen and potash are of relatively more impor- 
tance than phosphoric acid; that is, even where "exten- 
sive" practice is used there are conditions where one or 
more of the elements are not required in order to secure 
maximum crops, which eliminates the necessity for an 
immediate outlay for those constituents that are not 
lacking. Where experiments of this sort have not been 
carried out and the specific needs determined, it becomes 
necessary to assume that all of the constituents are 
required, and to apply the amounts and proportions of 
those which the general considerations of the soil, season, 
climate and crop would seem to demand. 

As already pointed out, the methods of fertilization 
here suggested, though in many instances apparently 
positive, are not to be interpreted as absolute rules, but 
rather used as guides, based upon the best information 
that it has been possible to obtain, both as a result of 
scientific inquiry and of practical experience. 

THE IMPORTANCE OF SYSTEM IN THE USE OF FERTILIZERS 

The following rotation is assumed, in order to show 
the necessity of a definite system of work, which is quite 
as important in this branch of farming as in many others 
in which system is apparently more essential, — though 
in fact it is quite as necessary to observe a definite system 



220 Fertilizers 

in the feeding of plants as in the feeding of animals with 

the plants. 

Illustration op a Rotation 

First year maize (corn) 

Second year oats 

Third year wheat 

Fourth year clover and timothy 

Fifth year timothy hay 

Indian corn exhaustive of the fertility elements. 

Since in rotations of this sort a fair number of live 
stock is usually kept, a considerable amount of ma- 
nure is made, which should be carefully cared for and 
used, as it contributes materially to the success of the 
plan. The manure may be used in part on land for 
corn, and should be spread broadcast, practically as 
fast as made during the fall, winter and early spring. 
Corn, because it is a gross feeder, and because it makes 
most of its growth during the summer season, when ac- 
tivities in the soil are most rapid, is able to appropriate 
from the coarse manures a larger proportion of the con- 
stituents than would be possible for crops which make 
their greatest growth earlier or later in the season. In 
the summer, too, the conditions are most favorable for 
nitrification, and soils which possess a fair content of vege- 
table matter are usually able to furnish the nitrogen needed 
in addition to that supplied in the organic manures, par- 
ticularly in the middle and southern states. The consid- 
erable amounts of potash required for the growth of stalks, 
and the phosphoric acid for the formation of grain, demand 
that a liberal supply of these constituents be provided, 
and the fertilizer for the corn should, therefore, contain 
an abundance of available phosphoric acid and of potash. 



PLATE X. 



Fertilizers and Tomatoes. 




Fig. 20. — Early Tomatoes Grown in Light, Sandy Soil, Thoro- 
fare, New Jersey. 




Fig. 21. — Growth of Clover along Tomato Rows Heavily Fer- 
tilized the Preceding Year, Moorestown, New Jersey. 



Fertilizers for Cereals and Grasses 221 

A crop of 50 bushels of shelled corn to the acre, with 
the accompanying stalks, will remove, on the average, 
80 pounds of nitrogen, 29 of phosphoric acid and 55 of 
potash. It is an exhaustive crop. A fertilizer, therefore, 
that would furnish 30 pounds of phosphoric acid and 40 of 
potash would be regarded as a fair dressing for land of 
medium quality, provided a liberal application of manure 
had been made to the land. A part of the phosphoric 
acid, at least, should be in a soluble form, in order to supply 
the early needs of the crop. The remainder may consist 
of ground bone or tankage, if the phosphoric acid in these 
can be obtained more cheaply, since they will decay 
rapidly enough to supply the demands for the later growth. 
The potash may be either muriate of potash or kainit, 
though the former is preferable if it is applied in the drill, 
which is, if used in these amounts, a perfectly safe practice 
so far as injury to the plant is concerned ; though ferti- 
lizers containing large amounts of potash salts are prefer- 
ably applied broadcast on raw ground of a clayey nature, 
and well worked into the soil, thus insuring a good distri- 
bution. The cost of an application of this sort will be 
relatively small, and the minerals added will be more 
than sufficient to provide for a considerable increase in 
crop. 

This recommendation is general and applies more par- 
ticularly to soils of high natural fertility. The soil, crop- 
ping system and method of manuring have much to do 
with the fertilization of corn. If the land is light and 
sandy, nitrogen should be added, even though it has re- 
ceived a good dressing of yard manure, as these lands are 
usually deficient in this element, and organic forms are 
usually quite as useful as the soluble nitrate or ammonia, 
since the seasonal conditions during the period of growth 



222 Fertilizers 

are favorable for the rapid change of the nitrogen in mate- 
rials of good quality, like blood, concentrated tankage, 
or cotton-seed meal, into nitrates. The amounts of 
nitrogen needed would, under ordinary conditions, be sup- 
plied by 100 pounds of high-grade blood, or 200 pounds 
of cotton-seed meal, or by deriving equal parts of the 
nitrogen from nitrate of soda and tankage. Other 
changes are also required according to the cropping system. 
In the rotation mentioned above corn follows a timothy, 
which, if properly top-dressed each spring, supplies a large 
amount of organic matter, and fertilizer may be used in 
smaller quantity, and a smaller amount, especially of 
the more slowly available nitrogen, may be included in 
the mixture. The same is true if a rank leguminous cover- 
crop is plowed under or if the ground is heavily manured. 
If corn is grown for grain one year and silage the next, a 
more abundant application should be made the second 
year ; 20 pounds of nitrogen, 30 of phosphoric acid and 40 
of potash is none too liberal. 

Whatever the practice of cropping, in this matter of 
fertilizing, it must be remembered that weeds appropriate 
plant-food quite as readily as the corn, wherefore in order 
to obtain the best results from the fertilizers added, clean 
cultivation should be practiced. 

Oats. 

For the oat crop that follows corn, and which makes 
its best growth early in the season, before nitrification 
is rapid, quickly available forms of nitrogen are very 
desirable ; and inasmuch as the oats require an abun- 
dance of phosphates, a fertilization with phosphoric 
acid is also essential. Hence, fertilizers consisting of 
mixtures of nitrate of soda and superphosphates have 



Fertilizers for Cereals and Grasses 223 

proved of great value for this crop. An application of 
8 pounds of nitrogen and 18 of phosphoric acid, or 200 
pounds to the acre of a mixture of 50 pounds of nitrate 
of soda and 150 of acid phosphate, has proved quite as 
profitable on medium soils as heavier applications, mainly 
because the oat crop is a less certain one than corn ; be- 
sides, it frequently suffers severe losses in harvesting, which 
increase the risk from an expensive fertilization. The 
application of potash is not so necessary if added in the 
fertilizer for corn, as suggested, except on light, sandy 
soils. 

It is not a profitable practice to use much manure in 
oats land, if any, because it is liable to cause a stalky 
growth and subsequent lodging and loss in harvest, and 
furthermore, it may be utilized so much more profitably 
for corn or some other crop which makes more of its growth 
in mid-summer when the soil activities are at their greatest. 

Barley. 

The fertilizer requirements of barley are similar in 
many ways to those of oats, although greater care should 
be used in the application of nitrogen, especially should 
the object of their growth be for malting. For this pur- 
pose, a plump, heavy, well-ripened grain, rich in nitrogen, 
is required. Too rank a growth of straw, caused by an 
abundance of nitrogen, is often accompanied by immaturity 
of grain ; besides, in moist seasons it is also likely to assist 
in the promotion of rust. 

A fertilizer, therefore, which will help to avoid these 
dangers, and at the same time supply the needs of the 
plant, may be made up of 50 pounds of nitrate of soda, 
150 of acid phosphate and 25 of muriate of potash to the 
acre. This mixture used at the time of seeding will supply 



224 Fertilizers 

the needed minerals and sufficient nitrogen to give the 
plants a good start. From three weeks to a month after 
seeding, an application of 50 to 75 pounds of nitrate of 
soda to the acre will help to insure a proper development 
and maturity, and provide for the largest yield of grain 
without injuring the quality for malting purposes. 

Wheat. (See Fig. 15, Plate VIII.) 

The fertilizing of wheat will depend largely upon 
the treatment of preceding crops. For wheat following 
the oats crop, the remainder of the manure may be ap- 
plied before plowing, well harrowed into the surface soil, 
and a fertilizer rich in available phosphoric acid, and con- 
taining only a sufficient amount of nitrogen in available 
forms to insure a good fall growth applied. When the 
land has been well fertilized for previous crops, a dissolved 
animal bone superphosphate is an excellent fertilizer, 
because it contains the elements, phosphoric acid and 
nitrogen, in good forms and proportions. Dissolved bone, 
however, is rather scarce and an expensive source of plant- 
food, and a mixture composed of 25 pounds of nitrate of 
soda, 75 of ground bone, 200 of acid phosphate and 25 
of muriate of potash will give quite as satisfactory results. 
If more nitrogen is needed than is provided by 200 to 
300 pounds of this fertilizer in order to mature the crop, 
which is frequently the case, particularly if the winter has 
been severe, or if the land is light, it may be applied in the 
spring, and preferably in the form of a nitrate, which dis- 
tributes readily, and is immediately available, advantages 
not possessed by other forms. At this period of its growth, 
the crops need to make a rapid appropriation of nitroge- 
nous food, though the conditions are not yet favorable for 
the change of nitrogenous organic compounds in the soil 



Fertilizers for Cereals and Grasses 225 

into the available nitrate. The top-dressings should 
be made as soon as the crop has been well started, and 
should range from 75 to 150 pounds to the acre, according 
to the character of the soil and previous fertilization. 
The better the natural character of the soil and its treat- 
ment, the larger the dressing that may be applied with 
possible profit, though in no case should it exceed the larger 
amount. In many cases it is advisable to make the spring 
application of nitrate of soda at intervals of two weeks or 
more. 

Rye. 

Rye is often used in this rotation, especially when a 
poor field comes around, because it is often considered a 
scavenger. In spite of this it is a crop which responds to 
good cultivation and fertilization. The use of a ferti- 
lizer, rich in phosphoric acid and available nitrogen, is 
especially recommended. An application of 50 pounds 
of nitrate of soda, 200 of acid phosphate and 25 of muriate 
of potash should supply ample food to insure a good fall 
growth. 

In order to provide an abundance of available nitrogen 
for a maximum crop of both straw and grain, the rye 
should be top-dressed in spring with at least 100 pounds of 
nitrate of soda to the acre, broadcast, just as soon as the 
plants start. At this season of the year, the requirements 
of the plant are the greatest, and the supply of available 
nitrogen in the soil very meager ; hence such an applica- 
tion fully meets the special needs of the plants for nitrogen. 

Clover. 

There are a number of types of clover which are sown 
in wheat when the ground is honeycombed in spring and 



226 Fertilizers 

follow it as a crop. Among these, red, mammoth red, 
alsike and white clover should be mentioned. "As 
clover is a legume, it is not usually benefited by the addi- 
tion of nitrogenous manures, except in the early stages 
of growth. On soils not well supplied with vegetable 
matter, manures are very beneficial, primarily in correct- 
ing the deficiencies, and in providing a more favorable 
medium for the development of specific bacteria. The 
size of the crop will be measured to some extent, also, by 
the abundance of mineral elements, thus enabling the plant 
to employ to full advantage its capability of gathering 
nitrogen. In many cases, particularly on soils that are 
likely to heave, a mulch of manure is very beneficial as a 
protection." An application of 100 pounds of acid phos- 
phate and 50 of muriate of potash or one which will fur- 
nish 14 pounds of phosphoric acid and 25 pounds of 
potash to the acre marks the minimum dressing, and it 
may be applied with advantage immediately after the 
wheat is harvested. 

Timothy. (See Fig. 16, Plate VIII.) 

The timothy, the next crop in the rotation, is a member 
of the grass family, and is especially benefited by nitrog- 
enous fertilization, and top-dressings in the spring with 
nitrate of soda have proved of great value on soils well 
supplied with minerals, though experienced farmers have 
learned that better results are obtained if the minerals 
are applied with the nitrate, thus insuring a better growth 
and development of plant. A mixture made up of 100 
pounds of nitrate of soda, 150 pounds of acid phosphate 
and 50 pounds of muriate of potash, at the rate of 300 
pounds to the acre, is now used by many successful hay- 
growers. In an ordinary season, such an application may 



Fertilizers for Cereals and Grasses 227 

be relied upon nearly to double the timothy crop. Under 
some conditions a slight change of the mixture is advisable. 
Upon heavy soils or limestone soils, the muriate of potash 
may be reduced to one-half or even omitted entirely. The 
nitrate of soda may be increased in mixtures for the same 
type of soil to 150 pounds, but care should be exercised 
in this matter because too large a proportion of nitrate of 
soda is liable to cause too rapid a growth and subsequent 
lodging and "firing." It is often stated that nitrate of 
soda causes a light, leafy hay, but this is only true when the 
mixture is not properly balanced. It is not profitable to 
top-dress timothy sods unless there is a sufficient number 
of plants on the ground to make efficient use of the plant- 
food which is immediately available and subject to loss 
if not used. The proportionate increase in crop would be 
the same, but the increase in yield would not be large 
enough to show a profit over cost of application. In 
every instance the application should be made as soon as 
the crop has well started in the spring. 

The system of fertilization here outlined is not to be 
advocated except under circumstances where it is not 
possible or practicable to supply such an abundance of 
plant-food as will guarantee a maximum production, as 
in "intensive" practice, in which the yield is measured 
by climatic and seasonal rather than soil conditions, 
but rather such additions as will return a profit and at 
the same time tend toward the improvement of soil. 
This system is economical in the use of nitrogen, the 
most expensive element. It provides a sufficient amount 
of available plant-food to insure a reasonable increase 
in crop, and it is well adapted to lead the farmer by easy 
steps from the "extensive" to the "intensive" system of 
farming. 



228 Fertilizers 



A gain of fertility by the rotation system. 

Assuming that the increased yield of corn is 20 
bushels, with accompanying stalks, of wheat 10 bushels 
per acre, of oats 15 bushels, of clover | ton and of 
timothy ^ ton, the amounts applied will be practically 
sufficient to furnish all of the potash contained in this 
increase, and more than sufficient to meet the demands 
for phosphoric acid. That is, by this system there has 
been applied in the materials 30 pounds of nitrogen, 64 
of phosphoric acid and 80 of potash. While, if this in- 
creased crop was secured, the following amounts would 
be required: 71 pounds of nitrogen, 31 of phosphoric 
acid and 79 of potash. The considerable amounts of 
plant-food contained in the yard manure, and the gain 
from the roots and stubble of the clover, serve to supply 
the balance of nitrogen required, and to provide a store 
of unused residue for future crops. 

The method, if adopted, would be more rational, and 
likely to result in more satisfactory returns than the 
one now generally practiced, namely, to purchase with- 
out particular regard to the character of the materials 
furnishing the constituents, or their proportions, and 
to apply, on the average, even less per acre than is 
here recommended. Assuming that 200 pounds to the 
acre of the average corn fertilizer, showing a composi- 
tion of 2.5 per cent nitrogen, 8 of phosphoric acid and 
5 of potash, were applied only to the crops corn, oats 
and wheat, omitting both clover and timothy, there 
would have been added 15 pounds of nitrogen, 48 of 
phosphoric acid and 30 of potash, amounts of each too 
small to provide for a large increase in crop, provided all 
were needed. 



Fertilizers for Cereals and Grasses 229 

The necessity of adding more plant-food than is required 
by a definite increase in crop. 

It may be asked, why add more of the constituents 
than is necessary to provide for a definite increase in 
crop? Assuming that the average yield of the land is 
twenty bushels of wheat to the acre, and the aim is to 
secure thirty bushels, why not add the constituents in 
the amounts and proportions necessary to provide for 
this extra increased yield, rather than any excess of these 
amounts ? The answer is, that in order that such a 
result may be accomplished, the conditions would need 
to be absolutely perfect, so that the plant would have at 
its command the amount of food needed each day. If a 
period in the growth of the plant should be so wet or so 
dry as to prevent the plants from acquiring the food 
necessary for their continuous growth, there would be no 
opportunity for them to gather food faster, when the 
better conditions followed the unfavorable conditions, and 
thus to overcome the ill effects of the period of partial 
starvation. In other words, if there were only sufficient 
food to supply the plant under normal conditions of sea- 
son, the plant, after a period of time during which there 
was no growth, could not grow faster than it did before, 
hence it could not catch up in its growth and make a 
full crop. Furthermore, the plan of applying only that 
needed for the increase must necessarily assume that the 
plant-food is in the best forms, and that the physical con- 
ditions of soil are so perfect as to cause it to absorb and 
retain all the food applied, and in such a manner as to 
permit it to be readily obtained by the plant. A further 
advantage is to enable the clover plant in the rotation 
to fully exercise its power of acquiring nitrogen from the 



230 Fertilizers 

air. Moreover, if properly carried out, it fulfils the idea 
of successful agriculture; viz., the production of profit- 
able crops, while at the same time not reducing, but 
increasing, the potential fertility of the soil. 

The system should be modified if no farm manures are used. 

In this rotation, if no manures are available, as indi- 
cated, then the amounts and kinds of fertilizers should 
be somewhat changed. For example, if it was necessary 
to supply the corn crop with a sufficient abundance of all 
the elements in artificial forms, then the proportions of 
nitrogen should be somewhat greater and the total amounts 
of the constituents applied to the different crops consider- 
ably increased. For corn, a mixture consisting of 20 
pounds of nitrogen, 30 of phosphoric acid and 50 of potash 
should be applied, and if grown upon raw ground rather 
than upon sod, it would be desirable to still further in- 
crease the nitrogen. The oats could be fertilized, as 
before recommended, while the wheat should have an 
increased supply of both nitrogen and phosphoric acid, 
— double the amounts recommended when used with 
manure, — besides an addition of at least 10 pounds to 
the acre of potash. The fertilizing of the clover and tim- 
othy need not be changed. If, in a rotation of this char- 
acter, barley were substituted for oats, and rye for wheat, 
the fertilization need not be materially changed, though 
the rye possesses a slightly greater power of acquiring 
phosphoric acid than wheat, and the nitrogenous top- 
dressings may be omitted, unless the crop is grown 
primarily for straw rather than for grain. The barley 
is also less able to acquire its phosphoric acid than the 
oats, and is especially benefited by nitrogen, though care 
should be exercised to regulate the amounts applied in 



Fertilizers for Cereals and Grasses 231 

order to prevent lodging, which affects both the yield and 
quality of the grain. If in the rotation the timothy hay 
is omitted, then the fertilization for the corn may be 
reduced, as on good soils the yard manure, together with 
the plant-food stored in the surface in the clover sod, will 
furnish an abundance. 



FERTILIZERS FOR A SINGLE CROP GROWN CONTINUOUSLY 

When it is desirable to grow any one or all of these 
crops continuously (and this practice may be followed 
with advantage, particularly when a leguminous catch- 
crop is seeded with the main crop, which insures a contin- 
uous occupation of the land and also provides vegetable 
matter and nitrogen), the fertilization would naturally 
be somewhat different, and, as a rule, would require more 
nearly even quantities of the different constituents. For 
corn, a fertilizer supplying 20 pounds of nitrogen, 40 each 
of phosphoric acid and potash, would provide for a liberal 
increase in the yield from year to year. The nitrogen 
should preferably be in good organic forms, which would 
decay rapidly enough to supply the needed available nitro- 
gen during the growing season. The phosphoric acid 
may be drawn partly from superphosphates and partly 
from organic compounds, as ground bone and tankage, 
provided these latter may be secured at as low a price 
as the superphosphate, and the potash applied in the form 
of a muriate or kainit. Fertilizers may be applied broad- 
cast and well harrowed into the soil, or part may be dis- 
tributed in the row at time of planting. 

If a catch crop were seeded to be used as green-manure, 
as, for example, crimson clover, the application of nitro- 
gen may be very materially reduced. This practice has 



232 Fertilizers 

been followed with advantage in the middle and southern 
states. 

For continuous wheat-growing, a fertilizer may be 
used at time of seeding which supplies 10 pounds of 
nitrogen, 40 of phosphoric acid and 20 of potash. A 
small part of this nitrogen would better be in the form 
of a nitrate, which will encourage a good top-growth 
in the fall, as well as a deep root system ; the phosphoric 
acid should be soluble, in order to supply the immediate 
needs of the young plant, and the potash in the form of a 
muriate. Such an application would provide for a very 
considerable increase in crop, particularly if followed in 
the spring by a top-dressing of 100 pounds to the acre of 
nitrate of soda. 

The top-dressing with nitrate of soda is, however, 
not always advisable. The chief objection to its use is 
that it does not encourage, but frequently seems to retard, 
the growth of clover, though its very great advantage is 
that it encourages the deeper rooting of the wheat and 
the more rapid growth of grasses. If continuous cropping 
of wheat is practiced, clover should be seeded with it, 
in order that the ground may be constantly occupied, 
and thus prevent leaching, as well as mechanical losses 
of fertility, and also to supply vegetable matter containing 
nitrogen for the succeeding crop. When a system thus 
outlined has been continued for a few years, the nitrogen 
in the fertilizer may be largely omitted. 

The same considerations apply to rye as were indicated 
for wheat. Oats are seldom grown as a continuous 
crop, though if it should be desirable, a fertilizer furnish- 
ing at least 20 pounds of nitrogen, 25 of phosphoric acid 
and 10 of potash would be a good dressing, care being 
taken that a large portion of the nitrogen exists as nitrate 



Fertilizers for Cereals and Grasses 233 

or as ammonia, in order to stimulate and strengthen the 
early growth of the plant. For the grass crop, or con- 
tinuous mowing land, a fertilizer rich in nitrogen and 
potash should be applied. A good application in the 
spring may consist of 25 pounds of nitrogen, 15 of phos- 
phoric acid and 25 of potash, and immediately after the 
hay is harvested a further application of at least 20 pounds 
of nitrogen and 30 each of phosphoric acid and potash 
should be applied. The nitrogen in this case may consist 
partly of organic forms, though the soluble nitrogen is 
to be preferred as top-dressings where it can be procured 
at such a price as to make it comparable with other forms. 
The nitrogen of bone, tankage and other slower-acting 
forms is excellent for the grasses, though these should be 
preferably applied and well worked into the soil previous 
to seeding. The early spring application should consist 
largely of soluble nitrogen, both to encourage a rapid 
appropriation of this element by the plant early in the 
season, as well as a deeper root-system, and consequently 
a greater drought-resisting power, and also to provide 
the elements necessary for the increased crop. The 
summer or later application stimulates and strengthens 
the roots for the coming season. If an aftermath crop is 
removed, or if it is pastured, a further application may be 
made which may consist largely of the mineral elements. 
This fertilization of the hay crop will also result in a richer 
product, for an abundant supply of nitrogen encourages a 
larger proportion of leaf growth, and consequently a smaller 
proportion of stem, containing the less valuable woody 
matter. Lands that are well fertilized in this way, if 
properly seeded in the first place, may make profitable 
mowing crops for a long series of years, and good crops 
cannot be expected unless liberal fertilization is practiced. 



234 Fertilizers 

FERTILIZERS FOR MEADOWS 

For meadows used as pastures, a more liberal appli- 
cation of the mineral elements is recommended, since 
an abundance of these encourage the growth of the 
clovers, which make a richer herbage than the grasses. 
Heavy nitrogenous fertilization is expensive, and en- 
courages the growth of the grasses rather than the clovers. 
Pasturing, while less exhaustive than hay cropping, 
nevertheless results in the gradual depletion of fertility, 
and an abundant growth of rich pasturage can only be 
secured where there is an abundant supply of available 
plant-food. Mixtures made up of acid phosphate, ground 
bone and muriate of potash in equal proportions make 
very good dressings, if applied in sufficient quantity, 300 
to 500 pounds to the acre annually. The ground bone is 
recommended because it decays slowly, and thus fur- 
nishes a continuous supply of nitrogen and of phosphoric 
acid. The application should preferably be made both 
in spring and in late summer, in order to secure a good 
growth, as well as to encourage the introduction of the 
clovers. Pastures become very acid in time and the ap- 
plication of lime is important. The carbonate form or 
ground limestone usually produces best results. Appli- 
cations of 500 pounds annually or a single application of 
one and one-half tons every five or six years should be 
made. If caustic lime is used, an application of 1500 
pounds every four or five years should be sufficient, though 
the first application might be much more liberal. In 
any system of continuous cropping, or in fact in any sys- 
tem of rotation-cropping, in which an abundance of 
organic matter is introduced in the way of green crops, 
or in decaying vegetable matter contained in roots, the 



PLATE XI. — Peppers and Red Clover. 




Fig. 22. — Peppers Grown under Field Conditions, Thorofare, 
New Jersey. 




Fig. 24. — Excellent Second Growth of Red Clover on Heavily 
Fertilized Potato Land, Freehold, New Jersey. 



Fertilizers for Cereals and Grasses 235 

land should occasionally receive a dressing of lime, both 
to supply that which the plants need, as well as to correct 
possible acidity of soil. 

WILL THIS SYSTEM OP FERTILIZING PAT? 

That fertilization will pay if carried out, as is 
pointed out here, and upon lands not now producing 
paying crops, depends, of course, very largely upon 
the price of the crops, the cost of the materials, and 
the method of farming practiced. At the prices 
which have prevailed in the recent past, for both 
crops and fertilizing materials, there is no doubt 
that this reasonable fertilization, together with a good 
system of practice in other respects, — that is, good 
plowing, good harrowing, good drainage and good culti- 
vation — will result in very satisfactory returns. In 
fact, it has been shown by repeated experiments (see 
bulletins and reports of New Jersey Experiment 
Station) that the yields on land which is capable of 
producing an average crop of 15 bushels of wheat to 
the acre, 30 of corn and 30 of oats, may be more 
than doubled by an abundant supply of fertilizing 
materials. Such an increase results in an actual di- 
rect gain, as well as in the saving of labor per unit 
of product, which is accomplished when the larger 
crop is secured. 

The main point in this whole matter of fertilization 
is to understand that a fertilizer is a fertilizer because of 
the kind and form of plant-food contained in it ; and that 
its best action, other things being equal, is accomplished 
when the soil possesses good physical qualities, when the 
management is also good, and when systematic methods 



236 Fertilizers 

are planned and adopted. "Hit or miss" fertilization, 
even for these crops, may pay, and doubtless on the aver- 
age does pay as well as some other things that farmers do, 
but does not pay as well as it might if better methods were 
used. 



CHAPTER XIII 
FIELD TRUCK CROPS 

The truck crops differ from cereals and grasses in that 
they are products of high commercial value, and are less 
exhaustive of plant-food constituents, that is, when money 
value is made the unit basis. They are termed "field 
truck crops" because they are field crops, usually grown 
in rotation and form a special crop for the grower which 
is produced solely for market rather than for manufacture 
upon the farm into a farm product. In sections near large 
markets these crops are divided into early and late, the 
early crop being regarded as the more profitable; hence 
greater efforts are made, both in the way of fertilization 
and of management, to secure a large and early crop, than 
is the case with the late crop. For the early crop the nat- 
ural supply of plant-food in the soil is not a prime consid- 
eration. In districts distant from markets, the late crop 
is the only one grown to any extent, and because it has the 
whole season for its growth, greater dependence is placed 
upon the natural resources of the soil. While, as already 
stated, these crops are not regarded as exhaustive of plant- 
food elements in the same sense as the cereal crops are, 
because it frequently happens that a bushel of potatoes, or 
of sweet potatoes, or of tomatoes, will bring as much as a 
bushel of corn, or sometimes as a bushel of wheat, yet the 
amount removed in the entire crop may be quite as great 
as in the grain crop, because of the much larger number 
of bushels grown an acre. 

237 



238 Fertilizers 



FEETILIZERS FOR POTATOES, EARLY CROP 

It has been demonstrated, both by experiment and 
practical experience, that good crops of early potatoes 
require an abundance of plant-food, and that on soils of 
good character a heavy fertilization is usually more profit- 
able than a medium or light application. 

The plant-food removed by a fair crop — 200 bushels to 
the acre of tubers — will, on the average, consist of 27 
pounds of nitrogen, 12 pounds of phosphoric acid and 60 
of potash. Even though the increase from the application 
of fertilizers is less than 100 bushels to the acre, it is always 
advisable to add plant-food in considerable excess of these 
amounts : first, because the crop must be grown quickly ; 
and second, because a large part of its growth must be 
made in the early season, before the natural conditions 
are favorable for soil activities. A study of the fertility 
composition of the potato shows that of the three essential 
constituents, the potash is contained in the greatest 
amount and the nitrogen next, while the amount of phos- 
phoric acid contained in it is comparatively small. Most 
fertilizer formulas for potatoes are therefore prepared with 
the idea of furnishing a greater amount of potash than of 
nitrogen or phosphoric acid. Studies made by the Geneva 
Experiment Station shows that the formulas prepared to 
contain the plant-food in nearly the proportions used by 
the entire potato plant, excepting that the phosphoric 
acid is in considerable excess, were less useful than 
those containing very different proportions of the con- 
stituents, and which were based upon the experience 
of observing growers. That is, a formula of the first 
class, furnishing — 



Field Truck Crops 239 

Nitrogen 6|% 

Available phosphoric acid 5% 

Potash 10% 

gave less satisfactory returns for the same amount applied 
than one furnishing — 

Nitrogen 4% 

Available phosphoric acid 8% 

Potash 10% 

This latter formula is very generally used in sections 
where early potatoes are an important crop. 

The time and method of application. 

These are matters of considerable importance. It 
has been urged, particularly by German experimenters, 
that the potash salts, when used in such excess as seems 
desirable, should be applied more largely to the crop 
preceding, rather than directly to the potato crop. This 
method has not been adopted in this country to any extent, 
and it is believed that our climatic conditions are such as 
to cause a very general distribution of the salts throughout 
the soil, if applied, in part at least, just before planting 
and thoroughly distributed by cultivation. At any rate, 
very satisfactory returns are secured from the direct ap- 
plication to the crop of fertilizers of this composition. In 
reference to the method of application, while very good 
results are secured from the application of the fertilizers 
directly in the row, this is to some extent influenced by the 
character of the soil. Where the soil is somewhat heavy, 
and the circulation of water is not perfectly free, it is less 
desirable than where the soils are open and porous, and 
free circulation is not impeded ; though where the 
amounts applied are considerable, it is recommended that 



240 Fertilizers 

at least one-half of the fertilizer should be applied broad- 
cast and worked into the soil, and the remainder placed in 
the row at the time of planting. Naturally, when the soils 
are poor, a concentration of the constituents is more de- 
sirable than when the surrounding soil possesses reasonably 
abundant supplies of available food. 

The amount to be applied. (See Fig. 18.) 

As already stated, the amount of the different constit- 
uents to be applied should be in considerable excess of 




Fig. 18. — The Potato-planter with Fertilizer Attachment, 
which distributes fertilizer evenly in the row. 

that required by the actual increase in crop, both for the 
reasons already given, and because it is desirable in crops 
of this sort to insure a continuous and abundant feeding 
of the plant. Where "intensive" practice is general, 
the amounts applied very frequently reach a ton to the 
acre of the high-grade fertilizer already mentioned, though 
the necessity for so large an application as this has been 
questioned, particularly if it is expected to give rise to a 
profitable return in the crop to which the application is 



Field Truck Crops 241 

made, and though it can be readily seen that if conditions 
should not be favorable, the larger amounts would be pref- 
erable. The result of investigations of this point by the 
Geneva Experiment Station showed that an addition of 
fertilizers above 1000 pounds to the acre, or 40 pounds of 
nitrogen, 80 of phosphoric acid and 100 of potash, was 
not as profitable as 1000 pounds. It must be remembered, 
however, that these experiments were conducted upon light 
soils, and on these entire dependence must be placed upon 
added plant-food. 

In the best potato sections of New Jersey, the applica- 
tion of a fertilizer of this composition ranges from 1000 
to 2000 pounds to the acre, while the larger part of the 
growers use the smaller rather than the greater quantity. 
(See Fig. 19, Plate IX.) Many use the larger, and are 
of the opinion that it is a profitable practice, because of 
the greater certainty of securing a good potato crop, and 
because the unused residue provides for large yields of 
the subsequent crop without further applications. The 
growers of potatoes in the vicinity of Norfolk, as well as 
farther south, also find it profitable to be generous in the 
use of fertilizer for this as well as for other crops of high 
commercial value. 

The growers of Maine use the larger quantity and many 
are now gradually changing the composition of the fertilizer 
applied by increasing the nitrogen to 5 per cent and de- 
creasing the potash to 7 per cent. It is not uncommon in 
Maine to make two applications during a season. This 
method has become known as the Aroostook County 
method. In some cases the fertilizer is merely divided 
into two parts and put on at intervals of three weeks or a 
month, but in other cases the first application made at the 
time of planting contains only organic nitrogen, whereas 



242 Fertilizers 

the second application contains nitrogen drawn from sol- 
uble sources. The second application is made when the 
vines are three or four inches high and the fertilizer is 
dropped right on them and then the entire plant is covered 
with soil. When this method is practiced, it is believed 
that more efficient use is made of the nitrogen, and that 
the vines have ample opportunity for increased root 
development. While this method is successful in Maine, 
it has not proved to be superior in New Jersey and warmer 
climates. It is applicable to both early and late potatoes. 

Form of the constituents. 

In the growing of potatoes, sulfate of potash is generally 
recommended in preference to the muriate, owing to the 
supposedly deleterious effect on the quality of the tubers 
resulting from the large quantities of chlorids contained 
in the muriate, though the different forms, when properly 
applied, do not seem to materially influence the yield. 
That is, if muriate or kainit is applied previous to the 
planting of potatoes, the deleterious chlorids derived from 
the muriate may be washed from the soil. There is no 
doubt that the sulfate improves the appearance of the pota- 
toes, making them more clean and uniform in size, though 
experiments that have been conducted do not show a 
material difference in the chemical composition of the 
tubers grown with any of the forms. The tendency on 
the part of the muriate seems to be to diminish the amount 
of dry matter, and inasmuch as the dry matter is mostly 
starch, the latter is thereby slightly reduced, though it 
has not yet been demonstrated that the good quality of 
the potatoes is measured by the content of starch. 1 

1 Bulletin No. 137, N. Y. State (Geneva) Exp. Sta. ; Bulletin 
No. 80, N. J. Exp. Sta. 



Field Truck Crops 243 

In reference to the form of nitrogen, both theoretical 
considerations and the experience of growers confirm 
the belief that for the early crop a portion of the nitrogen 
should exist in the form of nitrate or ammonia and the 
remainder in quickly available organic forms, although no 
definite experiments have been conducted to determine 
this point, nor the one as to whether all of the nitrogen in 
the form of nitrate should be applied at the time of plant- 
ing. A top-dressing after the potatoes have come up is a 
very desirable method of practice on light soils which 
have been liberally supplied with the minerals. 

On good potato soils, therefore, a good fertilization would 
consist of 1000 pounds to the acre, as a minimum, of a 
mixture containing : 

Nitrogen 4% 

Phosphoric acid 8% 

Potash 8% 

The nitrogen is to be in quickly available forms; the 
phosphoric acid, also, is to be available, and the potash to 
be derived from sulfate, particularly if fine quality of crop, 
as indicated by appearance, is desired. If only yield is 
considered, the muriate is quite as serviceable. 

LATE POTATOES 

For late potatoes, the considerations in reference to the 
form of the constituents and the amount of the application, 
as suggested for early potatoes, do not always hold good, 
since in many cases the crop is able to secure a larger pro- 
portion of its. plant-food from soil sources, — due, first, 
to the longer period of growth of the plant, and second, to 
the fact that the crop is usually grown upon soils naturally 



244 Fertilizers 

richer in the plant-food elements, though the proportion 
of potash, as in the formulas already indicated, should 
be relatively large. The nitrogen may be reduced, and 
the form of nitrogen may be derived largely from quickly 
available organic sources. Good formulas for late po- 
tatoes may consist of — 

Nitrogen 3% 

Phosphoric acid 6% 

Potash 8% 

and the application may be from 800 to 1200 pounds to 
the acre. 

Where potatoes are grown in rotations with the cereal 
crops mentioned in Chapter XII, the unused residue from 
the rather heavy application of fertilizers to the potato 
crop is depended upon to aid very materially the growth of 
these, thus reducing the outlay for fertilizer for crops of 
a low commercial value. This practice is advantageous, 
though the prime object should be to feed the crop rather 
than the soil — that is, apply the fertilizer with the idea of 
securing a profit from it in the potato crop, rather than a 
possible profit in subsequent crops. 

SWEET POTATOES 

In the growing of sweet potatoes, the quality of the prod- 
uct is more important than in the case of the white potato. 
The northern markets distinctly recognize quality in this 
crop, and it is measured by size, shape and results in cook- 
ing. The potato that brings the best price in the different 
markets is small, about the size of a white potato; in 
shape round, rather than oblong, and is dry and mealy 
when cooked. This characteristic of the crop is influenced 



Field Truck Crops 245 

both by the character of the soil and of the manures and 
fertilizers applied. The soils best adapted are dry, sandy 
loams, and the most useful fertilizers are those which 
contain an abundance of minerals — phosphoric acid 
and potash — and not too large supplies of quickly avail- 
able nitrogen. It is also true that the yields of sweet po- 
tatoes of this character are not as large as those that may 
be obtained when quality is not a prime consideration, and 
which are grown for the general market. 

Fertilizer constituents contained in an average crop. 

This crop is very similar to the white potato in regard 
to food required. Two hundred bushels of sweet pota- 
toes, not including vines, contain, on the average, 30 
pounds of nitrogen, 10 of phosphoric acid and 45 of potash ; 
and since the yield of the general crop is larger on the aver- 
age than one of white potatoes, a liberal supply of the 
minerals must in all cases be provided. The studies made 
of this crop have not yet established the best proportions 
of the constituents in fertilizers, though such experiments 
as have been conducted show that those that contain a 
very considerable excess of potash over the other elements 
are preferable. While nitrogen is needed, too much, 
particularly in soluble forms, seems to encourage too large 
a growth of vine, which contributes to yield, but at the 
expense of quality, which is a very important considera- 
tion. The best growers use fertilizers containing a small 
percentage of nitrogen and a high percentage of phosphoric 
acid and potash. Applications that furnish 20 pounds of 
nitrogen, 50 of phosphoric acid and 80 of potash to the 
acre have given excellent results in regions in New Jersey 
in which market quality up to a certain point is quite as 
important as increase in yield, though, of course, yield 



246 Fertilizers 

is also considered. Any excess of nitrogen over this 
amount seems to contribute toward a larger, rather oblong, 
rooty growth of tuber, and to injure cooking quality. In 
growing crops for the general market, however, larger 
applications of nitrogen are demanded, and experiments 
have shown that organic forms are preferable to soluble 
forms, though the climate and season largely influence 
this point. In northern sections, and in cold seasons, the 
soluble forms are more useful than in the warmer climate 
and longer seasons of the South. 

There is no question, however, that commercial fer- 
tilizers can be depended upon to produce maximum crops 
of sweet potatoes, and at much smaller cost than with 
yard manure. 1 Results reported by the Georgia Ex- 
periment Station 2 indicate the following formula as an 
excellent one for sweet potatoes, though, as there stated, 
" the amounts that can be used vary considerably, depend- 
ing upon the character of the soil — the richer the land in 
humus, the greater the quantity that can be safely used." 
" Thin soils will, of course, only stand very moderate ma- 
nuring, and necessarily produce a very small yield." The 
formula consists of — 

Acid phosphate 320 lbs. 

Cotton-seed meal • . . 360 lbs. 

Kainit 640 lbs. 

This formula will furnish about 25 pounds of nitrogen, 
50 of phosphoric acid and 80 of potash, and, according to 
the bulletin, will produce a yield of potatoes from 200 to 
400 bushels to the acre, depending upon the season and 
variety of potatoes planted. Experiments at the Georgia 

1 Bulletin P, New Jersey Exp. Sta. 

2 Bulletin No. 25, Georgia Exp. Sta. 



Field Truck Crops 247 

Station also show that organic nitrogen (cotton-seed meal) 
is preferable to nitrate of soda as a source of nitrogen. 

In making mixtures which furnish these proportions of 
plant-food, other nitrogenous organic materials furnishing 
an equivalent of nitrogen — as blood or concentrated 
tankage — may be substituted for the cotton-seed meal, 
if they can be purchased quite as cheaply ; and muriate 
of potash, furnishing an equivalent of potash, may be sub- 
stituted for the kainit, if it can be more readily obtained. 

As already stated, however, this fertilizer is too rich in 
nitrogen for the production of the best quality of potatoes, 
as, for example, "Vineland Sweets," which command the 
highest prices in northern markets. The growers in 
that district use a fertilizer richer in the minerals; one 
containing — 

Nitrogen 3% 

Phosphoric acid 7% 

Potash 12% 

is very generally used, though reasonably heavy dressings 
of this are often further supplemented by applications of 
from 200 to 300 pounds of acid phosphate and 100 to 150 
pounds of muriate of potash to the acre. 

The application of the fertilizers. 

Owing to the fact that the sweet potato is grown from 
plants or slips, rather than from seed, and the fact that the 
best quality of potatoes is produced upon rather light, 
sandy land, it is desirable that the fertilizer should be 
applied some time before the putting out of the plants. 
The practice on this light land is to apply the fertilizer 
when making up the hills, which usually occurs from two to 
three weeks before the plants are set. That is, in making 



248 Fertilizers 

up the hills, the soil is ridged, and during the preparation 
of the ridge the fertilizer may be distributed in it and well 
mixed with the soil. Where the land contains more clay 
and humus it is frequently advocated that the potash 
manures be applied broadcast the previous year, and only 
the nitrogenous fertilizer and superphosphate be applied 
immediately to the plant. On soils of this latter char- 
acter, this is doubtless the best system. If kainit — 
which has been found to be preferable to muriate in the 
Georgia experiments referred to — is used as the source of 
potash, it is very necessary that it be well mixed with the 
soil before setting out the plants. Heavy applications of 
this salt in the spring proved injurious in the experiments 
conducted at the New Jersey Station. The effect of 
fertilizers upon the chemical composition of the tuber was 
chiefly to reduce dry matter, and not apparently to affect 
edible quality, though the experiments were carried out 
upon the general crop rather than upon those grown for 
high quality. 

TOMATOES 

Tomatoes are largely grown as a field crop, and the ob- 
ject of their growth, whether for the early market or for 
the canneries, is a factor that must be considered in the 
adoption of systems of fertilization. 

Field experiments with fertilizers for tomatoes. 

The impression is very prevalent among growers that 
the tomato does not require heavy manuring. Studies 
made at a number of experiment stations show, however, 
that the tomato is a plant that quickly and profitably 
responds to the use of manures or fertilizers, and that the 
maturity and yield are very largely influenced by the 



Field Truck Crops 249 

method of manuring and fertilizing. Experiments were 
conducted by the New Jersey Station upon three farms 
located in different parts of the state, and during four sea- 
sons, the object of which was to test the effect on maturity 
and yield of the early crop of the use of nitrate of soda in 
different quantities and at different times, both with and 
without the addition of the mineral elements, phosphoric 
acid and potash, and to make a comparison of these with 
barnyard manure. The results showed : 

1. That nitrate of soda was one of the best nitrogenous 
fertilizers for this crop, and that its use in small quantities 
(160 pounds to the acre), or in large quantities (320 pounds 
to the acre) in two applications, increased the yield ma- 
terially, but not at the expense of maturity, and that this 
was equally true when used alone and when used in con- 
nection with phosphoric acid and potash. 

2. That nitrate of soda, when used in large quantities 
(320 pounds to the acre) in one application, in the presence 
of a sufficient excess of phosphoric acid and potash, did 
increase the yield, but at the expense of maturity. 

3. That when properly used, nitrate of soda was a 
profitable fertilizer for the crop. 

It was shown, furthermore, that nitrate of soda was 
superior to both barnyard manure and mineral fertilizers 
alone, and on the whole, was but slightly less effective 
than the complete fertilizers. 

Fertilizers for the early crop for different conditions of soil. 

These results have been practically confirmed both by 
the experiments of the stations referred to, and also in 
actual practice on soils similar in character; namely, 
those which were well adapted for the early tomato — 
light, well-drained sandy loams (see Fig. 20, Plate X) 



250 Fertilizers 

— and which had been previously well manured for crops 
entering the rotation. The results do not apply in the 
case of very poor soils, or upon heavy clay soils, which 
are not adapted for the early crop. 

The statement that it pays to fertilize early tomatoes, 
and that nitrate of soda is one of the best fertilizers for 
the crop, must therefore be accompanied by statements 
regarding the condition of soil and the purpose of growth. 
With the conditions clearly understood, a scheme of 
fertilization for early tomatoes may be outlined which, 
when the conditions are observed, will be likely to give 
much better results than methods of fertilization which do 
not take into consideration the habits of the plant and the 
special object of its growth. 

For example, on soils which have been well supplied 
with phosphoric acid and potash by manuring and fertiliz- 
ing previous to setting, a complete fertilizer containing 
sufficient nitrogen derived from nitrate of soda to start 
the plant nicely should be used. If as much as 80 pounds 
of phosphoric acid and 100 pounds of potash have been 
supplied, an application of 100 to 150 pounds of nitrate of 
soda alone may be used, followed by a side-dressing of 
150 to 200 pounds of nitrate of soda after the fruit has 
set and grown to about the size of walnuts. Care should 
be exercised not to make the application at the time of 
setting too large, because too rank growth often causes the 
plants to shed their bloom. A single application at the 
time of setting the plants would, perhaps, under good 
seasonal conditions give results quite as good, though 
the heavier application of nitrate at one time may result, 
in certain cases, in the loss of nitrogen by leaching, since it 
is an extremely soluble salt. In this case a deficiency of 
food would result, and thus prevent normal development. 



Field Truck Crops 251 

On soils which possess only good mechanical condition, 
and are very poor in plant-food, a heavier application of 
both nitrogen and the mineral elements will be required, 
in which case the following fertilization is recommended : 

Previous to setting the plants, or at the time they are 
set, apply 75 pounds to the acre of phosphoric acid, pref- 
erably derived from superphosphate, and 100 pounds of 
potash, derived from muriate, and thoroughly harrow or 
cultivate into the soil ; and at the time of setting apply 
around the hill 100 to 150 pounds to the acre of nitrate of 
soda. Three to four weeks later, make another application 
of from 100 to 150 pounds to the acre of nitrate of soda. 
Owing to the small bulk of nitrate, it should be mixed with 
dry soil or sawdust, in order to insure even distribution. 
The only precaution to be observed is to prevent its im- 
mediate contact with the plant roots. If these methods 
are practiced, the plant secures its nitrogen in an im- 
mediately available form at a time when it is needed, — ■ 
when it is set in the field. There is thus no delay in growth, 
and because of the presence of an abundance of the mineral 
elements, no excessive growth of vine is encouraged by the 
use of the nitrate, as would be the case were the mineral 
elements absent. Inasmuch as the nitrogen is applied 
close to the plant, it is within the immediate reach of its 
roots; and because it is all in an immediately available 
form, which is used up rapidly, the tendency to late plant 
growth, which would be caused by a continuous supply 
of nitrogen, is not encouraged, and a normal and rapid 
growth and development of fruit results. 

It is not stated that by this method of fertilization 
maturity is increased in the sense that the date of the first 
picking is earlier, but that a larger number of fruits is 
picked earlier. It was not shown in any of the experiments 



252 Fertilizers 

that the date of picking was made earlier by virtue of the 
nitrate, for, in fact, the earliest tomatoes were picked upon 
land where the minerals only had been applied. Here the 
yield was not satisfactory, but where the nitrate was 
applied, because of the larger crop, a larger proportion of 
early tomatoes was secured. It is obvious that, inasmuch 
as the price of the fruit rapidly declines as the season ad- 
vances, receipts from the proportionately larger quantity 
of early fruit will be materially increased. 

The use of fertilizers with yard manures. 

When it is desirable to use yard manures with fertilizers 
for tomatoes, because of the abundance and cheapness 
of the former, they should be applied broadcast, and the 
nitrate applied at the time of planting, as already described, 
rather than both together in the hill. The tendency in 
the latter case will be to cause a loss of nitrogen from the 
nitrate, depending upon the amount of organic matter 
in the manures. That is, experiments and experience 
have shown that under these circumstances more or less 
of the nitrogen in the nitrate may be lost. 

In the use of yard manures for early tomatoes, the ap- 
plication of excessive quantities should be avoided, as 
they are virtually nitrogenous manures, which, because 
of their organic character, feed the plant in proportion 
to their rate of decay. Hence, the presence of large quan- 
tities will encourage not only an undue growth of plant, 
but a late growth as well. The mineral fertilizers, as 
acid phosphate and muriate of potash, can be used with 
the yard manures with perfect safety, in fact, with great 
advantage, because they supplement the proportionate 
lack of mineral constituents. It is also desirable, where 
it is the practice to use manure, particularly if it is coarse, 



Field Truck Crops 253 

to spread it during the winter, in order that the soluble 
portions may become thoroughly distributed throughout 
the soil. As soon as the land is ready to work in the spring, 
it should again be plowed shallow and then deeply tilled, 
in order both to thoroughly warm up the soil, and to in- 
corporate with it coarser portions of the manure. 

Upon light, sandy soils coarse manure may be used, 
provided it is spread broadcast some time before working 
the soil; whereas, upon heavy, cold soils, well-rotted 
manure should be used and its application confined to 
the hill. 

Fertilizers for late tomatoes. 

In manuring and fertilizing for the late crop, the charac- 
ter of the crop and the season of its growth should be 
remembered. In the first place, the plants for this crop 
are not put in the soil until summer, when the conditions 
are most favorable for the rapid change of organic forms 
of nitrogen into nitrates. Thus, if the soil has been 
manured or is naturally rich in vegetable matter, the ad- 
ditional application of nitrogen in immediately available 
forms is not so important. In the second place, the object 
of the growth is not early maturity, but the largest yield of 
matured fruit ; hence it is more desirable to grow a larger 
plant than in the case of the early tomatoes. The fer- 
tilization should therefore be such as to furnish an abun- 
dance of all the elements of plant-food ; and, inasmuch as 
the tomato belongs to the potash-consuming class of 
plants, any fertilization should be particularly rich in this 
element. It is not to be understood, however, that it 
is not necessary to apply nitrogen, for frequently soils 
are used that are either not well adapted for the plant 
or are poor, not having been previously well supplied 



254 



Fertilizers 



with vegetable matter containing nitrogen. On such 
soils, additional applications are very important, and 
nitrate of soda is one of the best forms to use, as it is ab- 
sorbed freely by the roots, encouraging an early and vigor- 
ous growth of plant and a normal development of fruit. 
Slow-acting organic forms of nitrogen, on the other hand, 
frequently begin to feed the plant and cause its rapid 
growth when the energies should be concentrated in the 
growth and maturity of fruit. Fertilizers that have proved 
very excellent are those which contain a relatively smaller 
amount of nitrogen than is required for early tomatoes, 
and are richer in phosphoric acid and potash. 

A study of the composition of both the fruit and vine 
of the tomato will serve to guide us in this respect, though 
the amounts and proportions of food removed by any crop 
are not absolute guides, inasmuch as the soil may furnish 
more of one constituent than another, and because the 
plant may have the power of acquiring certain of its con- 
stituents more readily than others. The analyses of the 
fruit and vines of tomatoes show that one ton contains: 



In fruit . . 
Vines (green) 



Nitrogen, Lbs. 



3.20 
6.40 



Phosphoric 
Acid, Lbs. 



1.00 
1.40 



Potash, Lbs. 



5.40 
10.00 



Ten tons of the fruit, with the accompanying vines, 
which would probably reach four tons, would contain 
57 pounds of nitrogen, 16 of phosphoric acid and 94 of 
potash. On a good soil, therefore, which without manure 
would produce five or six tons, there should be added a 
sufficient excess of the constituents to provide for a maxi- 
mum production, and the materials should be relatively 



Field Truck Crops 255 

richer in nitrogen and potash than in phosphoric acid. A 
mixed fertilizer composed of : 

Nitrate of soda 300 lbs. 

Bone tankage 500 lbs. 

Acid phosphate 800 lbs. 

Muriate of potash 400 lbs. 

would contain, approximately, 75 pounds of nitrogen, 
156 of phosphoric acid and 200 of potash in each ton. 
An application of 1000 pounds to the acre of this mixture 
would furnish nearly half as much nitrogen as is contained 
in a crop of ten tons, a surplus of phosphoric acid, and an 
equal amount of potash. Hence a dressing containing the 
amounts, kinds and proportions of plant-food here shown 
would be regarded as very desirable, since one-half of 
the nitrogen is in the form of a nitrate, which would con- 
tribute to the immediate growth of the plant. The 
amount of soluble and available phosphoric acid is suffi- 
cient to satisfy the needs of the crop throughout its entire 
growth, and such an abundance of potash as to contribute 
to the normal development of both plant and fruit. For- 
mulas of this character have been used with good results, 
though the large proportion of salts sometimes make 
mixtures of this sort too moist to handle well, in which 
case a part of the potash, or even of the nitrate, may be 
applied separately with advantage. On poorer soils, 
the artificial supply of plant-food should be proportionately 
greater, or sufficient to provide for the entire needs of a 
fair-sized crop, since as a rule the relative power of the 
plant to acquire food is somewhat slighter on poor soils 
than on good soils ; or, stated in another way, the results 
from the use of fertilizers are proportionately better upon 
soils in good condition than upon those not well cared for. 
A good formula for these may consist of : 



256 Fertilizers 

Nitrate of soda 500 lbs. 

Bone tankage 500 lbs. 

Acid phosphate 400 lbs. 

Muriate of potash 600 lbs. 

One ton of this mixture would furnish, approximately, 
105 pounds of nitrogen, 120 of phosphoric acid and 
300 of potash. The application of 1000 pounds, there- 
fore, would furnish the food in sufficient abundance and 
in good proportions to meet the demands of a fair crop. 
There is a contention prevalent among large growers of 
late tomatoes that ammonium sulfate as a source of nitro- 
gen causes injury, and it is thought best to omit it even 
though there are not reliable experiments to prove this 
contention. 

The advantage of using so large a proportion of nitrogen 
in the form of nitrate of soda in this case is, that it is im- 
mediately available, inducing the immediate and rapid 
growth of plant, and preventing a too late growth by 
furnishing a minimum of organic nitrogen, which would 
become available late in the season. The cost of the 
fertilizer suggested in these cases is high, and the necessity 
of so expensive a dressing could be materially reduced 
by decreasing the need for nitrogen, particularly in organic 
forms, which may be accomplished by showing crimson 
clover with or after the previous crop of, say, corn or 
tomatoes. If weather conditions are favorable, crimson 
clover may be sown in the tomato fields in August, after 
cultivation has ceased, or at the last cultivation, and a 
crop of clover grown which will provide nitrogen for the 
next year's crop. This method is now practiced with 
advantage by many growers. The late crop, like potatoes 
and sweet potatoes, is usually grown in rotations in which 
it is the chief money crop ; hence the unused residue from 



Field Truck Crops 257 

fertilizers applied in large amounts, as here indicated, 
contributes largely to the economical growth of subsequent 
crops. (See Fig. 21, Plate X.) 

peppers and eggplant. (See Fig. 22, Plate XI.) 

It is not an uncommon practice to grow peppers and 
eggplant as a special crop under field conditions upon 
small farms, and often these plants may be seen occupying 
the same field. With these plants it is important that 
a liberal supply of quickly available nitrogen be supplied 
early in the growing season to produce early growth and 
strong foliage, although an excess should be avoided. It 
is a good practice to derive one-half of the nitrogen from 
quickly available organic materials. Before transplanting, 
the soil should receive not less than 1000 pounds of a 
mixture composed of 

Nitrate of soda 200 lbs. 

Dried blood, 16% am 150 lbs. 

Dried fish 150 lbs. 

Acid phosphate 1100 lbs. 

Muriate of potash 400 lbs. 

As soon as the plants are well established, a side-dressing 
of nitrate of soda should be used and immediately worked 
into the soil. This practice may be repeated twice or 
three times and the amounts to apply fixed accordingly. 
Upon light soils well-rotted yard manure may be used 
advantageously, especially when well worked into the 
soil. 

PEAS AND BEANS 

In canning sections, peas are grown upon large acreages 
and followed by bush beans. It is often the practice to 

s 



258 Fertilizers 

grow them year after year upon the same soil, and under 
such conditions it is necessary to give special attention 
to the fertilization. Because both crops are legumes, little 
nitrogen is needed except during the early stages of 
growth to start the plants well. For peas the nitrogen 
should be derived largely from available sources, 75 
pounds of nitrate of soda, 400 of acid phosphate and 100 
of muriate of potash should supply the needed plant-food. 
The beans which follow should thrive upon the residual 
fertility elements, but it is often well to make an additional 
application of 400 or 500 pounds of a mixture high in the 
mineral elements and deriving its nitrogen almost entirely 
from organic sources to prolong the period of growth. 
It should be remembered that these crops thrive best upon 
soils rich in organic matter, and it is a good plan to return 
the vines to the soil. 

FIELD BEANS 

Field beans, often called white beans, are grown ex- 
tensively for the food-stuffs market. This crop should 
be given different treatment than the garden bean because 
it is grown for the mature seed and the growing period is 
much longer. When grown in a rotation of beans, wheat 
and clover, little nitrogen need be used. When corn is 
included in the rotation, more nitrogen should be applied. 
In general, no less than 400 pounds of a mixture com- 
posed of 

Nitrate of soda 200 lbs. 

Dried blood 100 lbs. 

Acid phosphate 1300 lbs. 

Muriate of potash 400 lbs. 

should be used to the acre. 



Field Truck Crops 259 

GENERAL CONSIDERATIONS 

The foregoing crops differ materially from one another in 
many respects, though they are all heavy potash feeders. 
They are considered here primarily as special crops pro- 
duced upon general or dairy farms ; hence, it must be 
remembered that there are numerous factors which in- 
fluence the fertilization, chief among which are : the kind 
of soil, the rotation and system of fertilization and the 
length of growing season required by each. 



CHAPTER XIV 
GREEN FORAGE CROPS 

A large number of crops is included in this class. 
In dairy districts they are grown for summer feeding, 
mainly to supplement or to substitute pasturage entirely, 
as well as to provide a succulent ration of roughage in 
winter. Any crop which grows quickly, is palatable 
and makes a reasonably large yield, is adapted for the 
purpose. For convenience of study, these crops may be 
further classified into four groups : 1. cereals and grasses; 
2. clovers and legumes; 3. cole crops or the cabbage 
tribe ; 4. roots and tubers. 

CEREALS AND GRASSES 

In the case of those included in the first group, the 
purpose or object is to obtain as large a growth of leaf 
and stem as possible. Thus the character of the fertili- 
zation may differ from that recommended when the same 
crops are grown for the primary purpose of obtaining 
the largest yield of seed or grain. These crops, too, 
may in all cases be considered as only well adapted for 
the "intensive" system of practice — that is, when the 
management is such as to encourage the largest yield 
possible to the unit of area under the existing conditions 
of climate and season. The natural fertility of the soil 
thus becomes a less important factor; indeed it cannot 

260 



Green Forage Crops 261 

be relied upon altogether, as the largest yield of succulent 
food is dependent upon a rapid and continuous growth, 
and hence the supply of plant-food must be relatively 
much greater than is the case when the cereals are grown 
for their seed. That is, forage crops, because succulence 
is a factor influencing quality, must, as a rule, be grown 
quickly, and in order that large yields may be obtained 
in a short period of time a relatively greater abundance 
of plant-food must be at their disposal than when the 
growth is distributed through a longer period. Be- 
sides, larger amounts of all of the food constituents 
are required for the production of the same amount of 
dry matter to the acre than when grown for the mature 
crop, because the dry matter of the mature crop is richer 
in the constituents derived from the air and poorer in 
those derived from the soil, than the dry matter of the 
immature crop. 

Maize (corn) forage. 

A valuable forage crop of the first group is maize 
(Indian corn), because it grows quickly, is well adapted 
to a wide variety of soils and climates, is extremely palat- 
able, and is capable of producing large yields. The 
fertilization which has been recommended for the field 
crop is less desirable than one which furnishes a greater 
proportion of nitrogen, because of the greater need of 
this element, and because it encourages a larger leaf and 
stalk growth; and the greater the proportion of these in 
a corn crop, the richer will be the dry matter in the im- 
portant compound protein, and nitrogen is the basic 
element in this group of nutrients. 

When the crop is grown on good land on clover sod, 
which has been liberally manured, the fertilizers applied 



262 Fertilizers 

should be particularly rich in the mineral elements, phos- 
phoric acid and potash. An application of 500 pounds 
of a mixture containing — 

Nitrogen 2% 

Available phosphoric acid 6% 

Potash 8% 

would provide an abundance of food, even should un- 
favorable conditions intervene, but when grown on light, 
unmanured soil without sod, a larger amount of nitrogen 
should be used in connection with the minerals. An 
application of 25 pounds of nitrogen, 35 of phosphoric 
acid and 50 of potash is as small a fertilization as should 
be recommended on soils of this character, since a yield 
of 10 tons to the acre, containing 25 per cent of dry matter, 
— which is only a fair crop, — ■ would remove 60 pounds 
of nitrogen, 25 of phosphoric acid and 70 of potash. 
Hence, very large increases in yield could not be expected 
from smaller dressings, unless conditions were absolutely 
favorable throughout the entire period of growth. The 
nitrogen, as in the case of field corn, may be derived from 
organic sources, as the season of growth is the same, — 
the summer, — which is the most favorable for encouraging 
a rapid change of the organic nitrogen into the soluble 
nitrates. The phosphoric acid should be in large part 
derived from superphosphates, though since the season 
of growth and the character of the crop and of its cultiva- 
tion are conditions all of which favor a rapid change of 
insoluble into available forms, a portion may be sup- 
plied by ground bone or tankage. The potash may be 
kainit or muriate, though if kainit is used, it should 
be broadcasted and well worked into the soil before 
planting. 



Green Forage Crops 263 

Silage corn. 

Corn grown for the silo, while distinctly a forage crop, 
is, in its management, very similar to the field crop, and 
is not planted so thickly as to prevent the formation of 
ears. The object in its growth is, however, to obtain a 
large yield of dry matter, somewhat richer in nitrogenous 
substance and poorer in starch and woody fiber than field 
corn. Hence the fertilizers for the crop on medium soils 
should be richer in nitrogen than for the field corn, where 
the primary object is the grain, and where heavy fertiliza- 
tion with nitrogen would encourage a disproportionate 
stalk growth. An application of 30 pounds of nitrogen 
(equivalent to 250 pounds of dried blood or 450 of cotton- 
seed meal), 40 of phosphoric acid (equivalent to 300 
pounds of acid phosphate) and 60 of potash (equivalent 
to 120 pounds of muriate of potash) would provide for 
a marked increase in yield. 

Wheat and rye forage. 

In the growth of cereal grains, the object is to secure 
as large a yield of grain as is possible under the conditions 
of climate and season, and only such development of 
leaf and stem as will contribute to a maximum yield of 
grain. Hence a too liberal nitrogenous fertilization which 
encourages this form of growth may result in too great 
a proportionate yield of straw. This objection becomes 
an advantage when the cereals are grown for forage. 

The cereal crops, wheat and rye, if seeded in the fall, 
should therefore receive a fertilizer which shall especially 
promote leaf and stem growth; and to accomplish this 
purpose in the best manner, a rapid early fall growth, 
and a consequent deep rooting system, as well as an 



264 Fertilizers 

early and rapid spring growth, should be encouraged. 
Fertilizers most suitable are rich in nitrogen and phos- 
phoric acid, and should contain potash also, if the land 
has not been previously well supplied with this element. 
The larger proportion of the nitrogen, however, should 
be applied in available forms as a top-dressing in the 
spring, rather than at time of seeding, thus reducing the 
possible loss of this element during the winter and early 
spring through leaching, besides providing the plant 
with it when most needed, and producing a crop richer 
in nitrogenous substance. 

The ranker growth and somewhat coarser product 
resulting from this method of fertilization, while not 
desirable for grain crops, is not a detriment when the 
product is cut in its green stage for feeding, and the 
larger growth is accompanied by greater succulence. 

Where these cereal grains are sown mainly as catch 
crops following a corn crop which has been liberally fer- 
tilized with the minerals phosphoric acid and potash, 
the application at time of seeding may be light, and 
may consist only of nitrogen and phosphoric acid, — 
for example, from 200 to 400 pounds to the acre of a dis- 
solved bone; and the top-dressing in the spring need 
not exceed 100 pounds of nitrate of soda to the acre for 
the wheat, and 75 pounds to the acre for the rye. For 
lighter soils, or for those not previously well fertilized, 
much heavier applications not only are required, but all of 
the constituents should be included, and the top-dressings 
should be made in the spring, as already pointed out. 

Spring rye. 

For spring rye, an application of a fertilizer furnishing 
10 pounds of nitrogen, 20 of phosphoric acid and 10 of 



Green Forage Crops 265 

potash to the acre would be a sufficiently liberal dressing 
for the crop on good soils, since the plant possesses good 
foraging powers, though it is not so desirable a forage 
crop for northern climates as the winter rye. The ni- 
trogen, in any case, should be in quickly available forms. 

Oats. 

Oats and millet are also suitable crops for forage pur- 
poses, and are largely grown; the first, because it is 
adapted for cool, moist weather, and makes a rapid early 
growth, and the second, because adapted for late spring 
seeding and for summer conditions. 

The oat crop for forage purposes is even more generally 
benefited by manuring than when grown for the grain, 
and the constituents particularly useful are nitrogen and 
phosphoric acid, though on sandy soils, and on those of 
medium fertility and not previously fertilized with potash, 
this element should also be added. 

A good dressing, keeping in mind the value of the 
possible increased yield, may consist of 12 pounds of 
nitrogen, 20 of phosphoric acid and 10 of potash, — the 
nitrogen largely in the form of a nitrate and the phos- 
phoric acid in soluble and available forms. 

The oat crop is peculiar in that shortly after the 
germination of the seed there usually occurs a period of 
a week or ten days during which the growth is extremely 
slow, which experienced farmers call the "pouting" 
period. While the exact cause of this well-known habit 
is not understood, it is believed to be due in part to the 
absence of an available plant-food of the right sort early 
in the season, since liberal applications of nitrates and 
superphosphates seem to shorten the period of "pouting," 
if not altogether preventing its occurrence. Its avoid- 



266 Fertilizers 

ance for grain crops, while important, is not so impor- 
tant a matter as in the case of forage crops, since an ex- 
tension of the period of growth simply delays ripening,, 
while in the latter, delays not only prevent maximum 
growth within a certain time, but seriously interfere 
with rotations. 

Winter oats, which are successfully grown in the 
southern sections of the country, should be fertilized 
at time of seeding practically in the same manner as 
wheat; that is, dressings furnishing small amounts of 
nitrogen and considerable phosphoric acid, to be fol- 
lowed in spring with a top-dressing of nitrate of soda, 
not to exceed 100 pounds to the acre. 

Oats and peas. 

Where oats are grown with field peas for the purpose 
of supporting the vines, as well as to obtain a larger yield 
than from either alone, the fertilizer should also contrib- 
ute toward the increase in the pea crop, and hence a 
greater abundance of the minerals should be applied, 
though it is very desirable in this case, too, to encourage 
the rapid growth of the oats by reasonably liberal supplies 
of available nitrogen. (See Fig. 23, Plate XII.) 

Barley and peas. 

The growth of this combination of plants is a desirable 
one when late fall forage is needed, and as a crop, is well 
adapted for fall conditions. The fertilization should 
be liberal, in order to encourage a rapid and large appro- 
priation of food, which may be elaborated after light 
frosts occur. An application of 200 pounds to the acre 
of a mixture of 100 pounds of nitrate of soda, 175 of acid 
phosphate and 25 of muriate of potash will furnish suffi- 
cient and good proportions of the plant-food constituents. 



Green Forage Crops 267 

Millet 

The various kinds of millet are eminently surface 
feeders, and are particularly benefited by liberal ap- 
plications of all the fertility elements. In fact, maximum 
forage crops of this plant cannot be obtained except when 
there is present in the soil such an abundance of all of the 
fertility elements as to enable a continuous and rapid 
growth. Both the nitrogen and phosphoric acid should 
be largely in immediately available forms ; hence nitrates 
and superphosphates are recommended. The potash may 
be in the form of muriate. A crop of ten tons to' the 
acre of millet forage, of any of the Japanese varieties, 
which are very suitable for this purpose, will remove 50 
pounds of nitrogen, 25 of phosphoric acid and 110 of 
potash, practically all of which food is absorbed from the 
immediate surface soil. Good crops frequently reach this 
assumed yield ; hence, unless the land is in a high state 
of fertility, or has been previously fertilized, it is neces- 
sary, in order to obtain a fair crop, to furnish by direct 
application at least one-half of the nitrogen and potash, 
and as much phosphoric acid, as are contained in the crop. 
These amounts and kinds of plant-food could be practically 
supplied by a dressing of 450 pounds of a mixture made 
up of 150 pounds of nitrate of soda, 200 of acid phos- 
phate and 100 of muriate of potash, and such dressings 
have given excellent satisfaction in the New Jersey experi- 
ments with forage crops. 

Orchard-grass. 

Orchard-grass is among the earliest grasses that are 
useful for soiling or for pasture. It possesses many 
valuable characteristics, and is worthy of more careful 



268 Fertilizers 

attention than is usually accorded it. Its chief advan- 
tage lies in the fact that it is ready for use two or three 
weeks earlier than the grasses ordinarily grown; it is 
a plant, also, that makes a very heavy growth under good 
conditions of soil and season. 

Like other grasses, orchard-grass requires an abun- 
dance of available nitrogenous food, and therefore the 
promise of a crop is very much increased by the applica- 
tion of manures or fertilizers containing nitrogen at the 
time of seeding, and by top-dressing with nitrate of soda 
in early spring. A good formula or mixture for time of 
seeding is the following : 

Nitrate of soda 100 lbs. 

Tankage 200 lbs. 

Acid phosphate 600 lbs. 

Muriate of potash 100 lbs. 

An application of 400 to 600 pounds of such a mixture 
well harrowed into the soil with a spring top-dressing of 
100 to 150 pounds of nitrate of soda should amply supply 
the requirements of an abundant crop. 

Italian rye-grass. 

Another grass that has received some attention as a 
forage crop, particularly for summer pasture and soiling, 
is Italian rye-grass. It is especially suitable for moist 
soils, or for soils that can be irrigated, and responds 
very profitably to the application of water or heavy 
fertilization. The fertilization of this crop may be the 
same as that recommended for orchard-grass, except 
where irrigation is practiced, in which case less available 
nitrogen should be used because it is likely to be lost by 
leaching. 



Green Forage Crops 269 

Bermuda-grass. 

In the southern states, Bermuda-grass is considered one 
of the most valuable grasses for pasture. It is dis- 
tinctly a hot weather plant, and thrives only in those 
regions which have short, mild winters. Fortunately, it 
is well adapted for pasture on poor lands, and its power of 
withstanding a drought is one of its valuable characteris- 
tics. Because it is capable of producing a new plant at 
each joint, it spreads rapidly, and it is this quality which 
makes it a valuable pasture grass as well as an aggressive 
and pestiferous weed. However, it can be eradicated 
from a field where it is not wanted with comparative ease 
by proper cultivation. At the time of seeding, the soil 
should be well supplied with minerals, and top-dressings 
of nitrate of soda should be made in spring. 

CLOVERS AND OTHER LEGUMES 

There are four types of true clover — red clover and 
mammoth red clover, a variety of the former, alsike clover, 
crimson clover, white clover — which are among the most 
valuable of our summer forage crops: first, because of 
the time of their growth, they furnish food before spring- 
sown crops are ready ; second, because of their power of 
acquiring food from sources inaccessible to the cereals, they 
are less exhaustive ; and third, they are especially rich in 
the compound protein, the most useful substance con- 
tained in feeds. Since these crops generally grow well 
on soils of medium fertility, many are inclined to regard 
them as able to subsist and make a good crop without 
liberal fertilization. It should be remembered, however, 
that the power which these plants possess of acquiring 



270 Fertilizers 

nitrogen from the air depends largely upon the supply 
at their command of the mineral elements, phosphoric acid, 
potash and lime ; the presence of these is of primary im- 
portance, and good crops cannot be grown on land deficient 
in these elements. In any event, therefore, liberal supplies 
of the minerals should be provided, in order that maximum 
yields may be obtained. (See Fig. 24, Plate XI.) On soils 
of medium fertility which are fairly well supplied with 
vegetable matter, the need for nitrogen is not marked, 
even in the early growth of the plant. On lighter soils, 
however, a nitrogenous fertilization is often serviceable, 
because supplying nitrogen before the plant has acquired 
the power of obtaining it from the air. This practice 
enables the plant to make an early start, and prevents 
the delay in growth which sometimes occurs, particularly 
on light soils, during the period immediately after germina- 
tion, when the plant is unable to obtain its nitrogen from 
sources other than the soil. A green forage crop averaging 
10 tons to the acre requires, on the average, about 30 
pounds of phosphoric acid and 100 of potash, and the 
nitrogen which necessarily accompanies these amounts 
of minerals will reach, on the average, 100 pounds. If 
this element is drawn from the air, because provided with 
an abundance of minerals, it is manifestly economy to 
supply the full amount of these required, rather than 
omit them, and thus to limit the plant's power of acquiring 
this expensive element, since the value of the 100 pounds 
of nitrogen gained is greater than the cost of both the 
phosphoric acid and potash required. The fertilization 
of these various clovers may be much the same; in 
general an application of 200 pounds of acid phosphate 
and 100 of muriate of potash should be sufficient, espe- 
cially if they follow a well-fertilized crop, such as potatoes. 



Green Forage Crops 271 

Japan clover. 

Japan clover, though not a true clover, is valuable 
as a pasture crop because it is well adapted to poor and 
light lands and withstands drought well, growing and 
spreading when other plants die for lack of moisture. It 
thrives from Virginia southward and as far west as Kansas. 
It is seldom fertilized, even though it is much like other 
clovers and responds to liberal applications of the minerals. 

Cowpea and soybean. 

The clovers, which range in their length of life from 
annuals to perennials, are, too, able to obtain their neces- 
sary supplies of minerals more readily from soil sources 
than the distinctly summer crops, as the cowpea and soy- 
bean, because of the longer period of preparatory growth 
in the case of the former. That is, clover or vetch, while 
it does make a very rapid growth through a short period, 
does not obtain all of its food during that period. In its 
preparatory stage of growth — fall and early spring — a 
very considerable amount of food, the larger proportion, 
in many instances, is obtained, which in its later stages 
of growth is simply distributed throughout the entire 
plant ; while the cowpea and soybean, on the other hand, 
must obtain the entire amount of food needed for their 
growth and development during a short period, and these 
crops reach their best stage of development for forage 
in two and one-half «to three months from time of planting. 
Hence, these crops, which possess apparently greater 
foraging powers, and make their development during 
the season when conditions are most favorable for rapid 
change of insoluble to soluble food in the soil, require, 
when the conditions of the land are the same in each case, 



272 Fertilizers 

a relatively greater abundance of the mineral elements 
than do the clovers, which can acquire food through a 
longer period. 

An application of 300 pounds to the acre of a mixture 
of 200 pounds of acid phosphate and 100 of muriate of 
potash, which supplies 25 pounds of phosphoric acid and 
50 of potash, would, on medium soils, be regarded as a 
sufficient annual dressing for clover crops; whereas, in 
the case of the purely summer crops, the application 
could be increased one-half with profit. In the case of 
the summer crop, the phosphoric acid should be in a 
soluble form, because it is not economy to depend upon 
the conditions of climate, soil and season to change in- 
soluble forms rapidly enough to provide for the con- 
tinous feeding of the plant, while for the clovers, less 
available forms may be used with advantage. 

Spring vetch. 

Spring vetch may be substituted for Canada field peas 
in a mixture with oats ; and in the northern states, where 
the pea-louse has been very destructive, it serves an 
excellent purpose. It is sown in spring or early summer, 
and does not survive the winter. The preparation of 
soil and fertilization should be practically the same as 
recommended for oats and peas. 

Hairy or winter vetch. 

Hairy vetch is used extensively as a cover-crop or green- 
manure, and its use in combination with wheat or rye as a 
forage crop is increasing rapidly. The chief advantage of 
the use of hairy vetch with wheat or rye lies in the fact 
that a larger crop of forage may be secured than when the 
cereal is grown alone. The fertilization should be the 



Green Forage Crops 273 

same as recommended for the cereal with which it is grown, 
except that the amount of nitrogen may be slightly re- 
duced. A liberal supply of minerals should be applied. 

Alfalfa, or lucerne. 

This valuable crop, which was not formerly regarded 
as well adapted for the eastern states, can be success- 
fully and profitably grown if the soil is sufficiently deep 
and open and naturally well drained, and provided it is 
supplied with an abundance of mineral food, consisting 
of phosphoric acid, potash and lime. Its habits of growth 
are such as to enable the harvesting of three or four green 
forage crops, and at least two hay crops annually. In 
order to meet the large plant-food demands thus made, 
the fertilization previous to seeding must be not only 
liberal, but frequent top-dressings should be made. The 
phosphoric acid for these dressings should preferably be 
drawn from superphosphates, in order that ready dis- 
tribution may be accomplished, while a large portion of 
that contained in the preparatory dressing may consist 
of the less soluble forms, as ground bone, natural phos- 
phatic guanos, and fine ground rock phosphates. 

Twenty tons of alfalfa green forage, which may be 
regarded as a good annual yield for this plant from the 
two to four cuttings that may be made, will contain 
250 pounds of nitrogen, 50 of phosphoric acid and 275 
of potash. Assuming that the demands for soil nitrogen 
are confined to a short period immediately subsequent 
to the germination of the seed, the total required plant- 
food is still considerable, and is especially severe upon 
the potash compounds of the soil. Hence, the fertilizers 
supplied should be particularly rich in this element. For 
eastern conditions, where soils possess a medium rather than 



274 Fertilizers 

a high potential fertility, heavy dressings of the minerals 
should always be made. A good preparatory fertilizer may 
consist of 20 pounds of nitrogen, equivalent to 125 pounds 
of nitrate of soda; 75 of phosphoric acid, equivalent to 
600 of acid phosphate ; and 200 of actual potash, equivalent 
to 400 pounds of muriate of potash to the acre ; and an- 
nual top-dressings should provide at least 30 pounds of 
phosphoric acid and 100 of actual potash for the same area. 
Inasmuch as careful preparation of soil is necessary 
previous to seeding, and since this can preferably be 
accomplished by the growth of cultivable crops, the 
fertilizers may be also partly applied to these rather 
than all at once immediately preceding the seeding, 
thus limiting danger of injury to germination by an 
application of so large a proportion of salts. 

Sweet clover. 

The use of sweet clover is spreading very rapidly in 
the United States. While its growth and purpose of 
growth are very much the same as alfalfa, it does not 
seem to require nearly as much fertilization, and it is not 
uncommon to produce enormous yields of forage or hay 
upon good soils without any fertilization. Its culture 
may be the same as alfalfa, but it has been found more 
profitable in most localities to sow it in grain in spring 
when the ground is honeycombed. In this case no fer- 
tilization is needed. If sown alone, moderate quantities 
of the minerals should be supplied. It thrives especially 
well in hard, compact soils, rich in lime. 

Need of lime for legumes. 

Another point that should be remembered in the 
fertilization of the leguminous plants is their need for 



Green Forage Crops 275 

lime. This is true of the clovers particularly, not only 
for the purpose of providing the plants with a sufficient 
amount of this element, but in order that any possible 
acidity of soil may be corrected, since the bacterial life 
in the soil, which is essential in order that the plant may 
acquire its nitrogen from the air, is discouraged rather 
than encouraged by the presence of acid. Hence, all 
soils that are used for the frequent growth of leguminous 
crops should receive a dressing of lime, preferably in the 
fall ; 25 bushels of stone lime to the acre, or its equivalent 
of ground limestone. Once in four or five years is a 
sufficient amount for medium soils. 

Fertilization of soiling crops. 

The necessity for fertilization, and the method em- 
ployed in "intensive" practice, are illustrated by the 
following scheme of growing soiling crops, now practiced 
at the Experiment Farm in New Jersey. If an abundance 
of food is not supplied, the continuous feeding and con- 
sequent constant and rapid growth of the plants, which 
are primary necessities of the system in order to maintain 
the rotation and to obtain maximum yields, are prevented. 
With proper management in other respects, the scheme 
of rotation and fertilization will result in a gradual in- 
crease in the fertility of the soil. 

SCHEME OF SOILING CROPS 

No. of Crop Ro- Time op Amount of Time of 

Acre tation Seeding Fertilizer Applied Harvesting 



'Crimson clover . . Au g . 11, '97 { l«j £ ^It^oUsh } May 20, '98 

[ 100 lb. Acid phosphate 1 

Corn June 20, '98 50 lb. Ground bone | Aug. 20, '98 

I 50 lb. Muriate of potash J 

_ , , _ f 25 lb. Nitrate of soda 1 

Barley and Peas . Aug. 25, '98 100 lb Acid phosphate Oct. 25, '98 

I 50 lb. Muriate of potash J 



276 



Fertilizers 



No. of Crop Ro- 

ACRE TATION 



Crimson clover 



Corn 



Barley and Peas 



Time op 
Seeding 

Aug. 24, '97 | 
June 10, '98 

Aug. 25, '98 



3 ■ 



Millet 



Corn 



Barley and Peas 



Wheat 



Oats and Peas 

Soybeans . . 
Rye . . . 



Millet . . . 
Cowpeas . . 

Oats and Peas 

Soybeans . . 
Barley and Peas 



Corn May 20, '98 



Aug. 1, '98 

May 10, '98 

Aug. 10, '98 
Sept. 28, '97 

April 20, '98 

Aug. 1, '98 
Sept. 29, '97 

May 1, '98 
July 20, '98 { 



Amount op 
Fertilizer Applied 

100 lb. Acid phosphate 
50 lb. Muriate of potash 

100 lb. Acid phosphate 
50 lb. Ground bone 
50 lb. Muriate of potash 

25 lb. Nitrate of soda 
100 lb. Acid phosphate 
50 lb. Muriate of potash 

50 lb. Nitrate of soda 
100 lb. Acid phosphate 
50 lb. Ground bone 
50 lb. Muriate of potash 

75 lb. Nitrate of soda 
150 lb. Acid phosphate 
75 lb. Muriate of potash 

50 lb. Nitrate of soda 
100 lb. Acid phosphate 
50 lb. Ground bone 
50 lb. Muriate of potash 

25 lb. Nitrate of soda 
100 lb. Acid phosphate 
50 lb. Muriate of potash 

150 lb. Acid phosphate 
50 lb. Ground bone 
25 lb. Muriate of potash 

25 lb. Nitrate of soda 
100 lb. Acid phosphate 
25 lb. Ground bone 
50 lb. Muriate of potash J 

200 lb. Acid phosphate ) q t 



Time of 
Harvesting 

f May 10, '98 



Aug. 10, '98 



Oct. 25, '98 



July 20, '98 



Oct. 1, '98 



July 10, 'E 



Oct. 10, '98 



June 5, '98 



June 20, '98 



April 10, '98 

July 1, '98 { 
Sept. 1, '98 



100 lb. Muriate of potash 

150 lb. Acid phosphate 
50 lb. Ground bone 
25 lb. Muriate of potash 

75 lb. Nitrate of soda 
150 lb. Acid phosphate 
75 lb. Muriate of potash 

200 lb. Acid phosphate 
100 lb. Muriate of potash 

25 lb. Nitrate of soda 
100 lb. Acid phosphate 
25 lb. Ground bone 
50 lb. Muriate of potash 

200 lb. Acid phosphate 
100 lb. Muriate of potash 

25 lb. Nitrate of soda 
100 lb. Acid phosphate 
50 lb. Muriate of potash 



98 
May 1, '98 

July 1, *9S 
Sept. 20, '98 

June 10, '98 



} Sept 



OS 
Nov. 1, '98 



Green Forage Crops 



277 



No. of Crop Ro- 

ACRE TATION 



Oats and Peaa , 
Cowpeas . . 
Barley and Peas 

Rye and Vetch 
Corn . . . 
Barley and Peas 



Time op 
Seeding 



April 1, '98 

June 15, '98 
Aug. 20, '98 

Sept. 10, '97 

June 1, '98 

Aug. 15, '98 



Time of 
Harvesting 



June 1, '98 



Amount of 
Fertilizer Applied 

25 lb. Nitrate of soda 
100 lb. Acid phosphate 
25 lb. Ground bone 
50 lb. Muriate of potash J 

200 lb. Acid phosphate 1 . . , ,„„ 
100 lb. Muriate of potash / g- ' 

25 lb. Nitrate of 3oda ] 
100 lb. Acid phosphate \ Oct. 20, '98 
50 lb. Muriate of potash J 

25 lb. Nitrate of soda ] 
150 lb. Acid phosphate [ May 5, '98 
75 lb. Muriate of potash J 

100 lb. Acid phosphate ] 
50 lb. Ground bone [ Aug. 1, '98 

50 lb. Muriate of potash J 

25 lb. Nitrate of soda 
100 lb. Acid phosphate 
50 lb. Muriate of potash 



Oct. 15, '98 



This scheme, which provides for two or three crops 
each season, has proved entirely practicable and success- 
ful when liberal fertilization is practiced, as here indicated. 



THE CABBAGE TRIBE 

Several members of the mustard family of the cabbage 
kind are useful forage crops, and their cultivation is rapidly 
increasing. In general feeding practice, they may be 
compared with root crops. In fact, kohlrabi is often 
classed with root crops, and well it may be, since it is 
very closely allied to the turnips and rutabagas, differing 
chiefly in having the thickened part above the ground rather 
than below ground. The leading cabbage-like forage plants 
are rape, cabbage and kohlrabi. The kales are not much 
grown for forage in North America. Their culture does 
not differ greatly from that of rape. Thousand-headed 
kale is the kind mostly recommended, but it does not ap- 
pear to have any advantage over rape for forage. 



278 Fertilizers 

Rape. (See Fig. 25, Plate XIII.) 

Although rape does well in soils of medium fertility, 
the best results are secured when they are naturally 
rich, or have been well fertilized. When grown for 
forage, an application of barnyard manure at the rate of 
8 tons to the acre, well worked into the surface soil, is 
desirable, because the plant is a voracious feeder. For 
its best growth it must have abundance of available 
nitrogen. Hence, if manures are not readily obtainable, 
an application of fertilizers rich in nitrogen should be 
applied. Experience has shown that a fertilizer con- 
taining 

Nitrogen 5% 

Phosphoric acid (available) 8% 

Potash 9% 

applied at the rate of 600 pounds to the acre, will supply 
the food in good proportions. Should the season be 
unfavorable for rapid growth, an additional application 
of 100 pounds to the acre of nitrate of soda when plants 
have well started will stimulate growth and help to insure 
a large crop. This top-dressing of nitrate of soda should 
be made when the plants are dry. 1 

Cabbage. 

Among those forage crops grown for late use, there is 
none capable of producing the large tonnage which may 
be secured from cabbage when it is efficiently attended. 
It has not been grown to any extent in this country for 
feeding live-stock, but a knowledge of its value for this 
purpose is undoubtedly extending. It is a voracious 

1 Voorhees, " Forage Crops." 



Green Forage Crops 279 

feeder, and if it is to be grown successfully for forage it 
should be liberally fertilized. Twenty to 25 tons of 
manure should be applied before plowing, 1500 pounds 
of lime after plowing, and just previous to seeding 100 
pounds of nitrate of soda, 700 of acid phosphate and 200 
of muriate of potash to the acre. It is important that 
these applications be uniformly made, and that the lime 
should not be omitted, because it is a safeguard against 
a disease known as club-root or finger-and-toe. 

Kohlrabi. 

Kohlrabi attains its best development when grown upon 
rich soils, and proves a valuable forage crop, especially 
because it may be fed at any period of growth without 
risk. It may be grown upon any soils suitable to ruta- 
bagas, and its culture and fertilization may be the same. 

ROOT CROPS 

These crops are, as a class, exhaustive of plant-food 
elements, much more so, in proportion to the dry matter 
contained in them, than the cereals or legumes. It 
will require, for example, 20 tons of topped fodder-beets 
or turnips to furnish as much total food as is contained 
in 10 tons of corn forage or silage, as the former seldom 
contain more than 10 per cent of dry matter, whereas the 
latter frequently contain more than 20 per cent; yet on 
the average, 20 tons of roots will contain 60 pounds of 
nitrogen, equivalent to 400 pounds nitrate of soda, 35 
of phosphoric acid, equivalent to 300 pounds of acid 
phosphate, and 150 of potash, equivalent to 300 of muriate 
of potash, which amounts are far in excess of those con- 
tained in a corn crop, particularly of the minerals, phos- 



280 Fertilizers 

phoric acid and potash. The nitrogen demands for the 
two crops are practically identical. In the case of both 
kinds of crops, these fertility constituents are obtained 
entirely through the roots from soil sources. 

In respect to fertilization, however, the root crops 
may be divided into two groups, very similar in their 
demands for plant-food, the first to include mangel- 
wurzels, fodder-beets, sugar-beets and carrots, and the 
second turnips, swedes (rutabagas) and rape. 

Fertilizers for fodder-beets, sugar-beets and carrots. 

The first group requires that the fertilization with 
nitrogen and phosphoric acid shall be liberal, and that 
these constituents shall be applied in readily soluble 
forms, in order to meet the large and early demands of 
the plant for them. Potash is also a very essential 
constituent, particularly upon soils of a light, sandy 
character; upon clay loams the plant is better able to 
obtain this element. 

In order to obtain a large amount of actual food by 
the growth of these crops, a large tonnage must be secured, 
and a large yield cannot be obtained unless provision is 
made for a continuous and rapid growth, and this again 
cannot be accomplished without an abundant supply of 
nitrogen and phosphoric acid, which, as already stated, 
are the elements which, more than any others, seem to 
rule the crop. 

In the case of sugar-beets, the suggestion for fertiliza- 
tion when grown for sugar (Chapter XVII) may be fol- 
lowed in large part. That is, particular attention should 
be given to the supply of nitrogen and phosphoric acid, 
though when grown for forage it is important not only to 
secure sugar, which constitutes a large proportion of the 



Green Forage Crops 281 

dry matter, but that the gross yield shall be much greater 
than in the former case. Hence, a liberal use of yard 
manure need not be avoided, and heavier dressings of 
nitrogen, which stimulates early leaf growth, may be 
made. 

For both fodder-beets and sugar-beets, an application 
to the acre of 40 pounds of nitrogen, 50 of phosphoric 
acid and 100 of potash, or 1000 pounds of a fertilizer, 
containing — 

Nitrogen 4% 

Available phosphoric acid 5% 

Potash 10% 

should insure a very considerable increase in yield on 
soils of medium fertility, provided the elements are drawn 
from the best materials. On light soil the fertilization 
should be still heavier, and the proportion of nitrogen 
increased. In fact, on soils poor in fertility and possessing 
good physical qualities, the contributions of plant-food 
by them may be largely ignored, and the dressings made 
large enough to supply the entire amount of food required 
by the crop. On such soils the nitrogen should prefer- 
ably be applied in fractional dressings and in quickly 
available forms, because it is essential that this element 
should be quickly absorbed by the growing plant. The 
minerals may be all applied in one dressing, though 
preferably in two, in order that the constituents may be 
well distributed throughout the surface soil. To better 
accomplish this, cultivation should follow each application. 

Turnips and swedes. 

In the case of the second class of crops, it has been 
shown that they are able to extract their phosphoric acid 



282 Fertilizers 

from combinations not readily accessible to other plants. 
In fact, they respond so promptly to applications of this 
element that frequently too little attention is given to 
the supplies of the other elements ; yet in order to obtain 
satisfactory yields, these must also be added. An anal- 
ysis of the turnip, for example, shows it to be rich in 
potash; hence it must naturally be a voracious feeder 
upon compounds containing this element, and while it 
seems to obtain it more readily from soil sources than 
many other plants, these supplies should not be depended 
upon, even on good soils, to meet its entire needs in this 
respect. A liberal supply of nitrogen is also demanded, 
particularly during the early growth. An application of a 
fertilizer containing 20 pounds of nitrogen, derived in part 
from nitrate, 40 of phosphoric acid, derived in large part 
from phosphates, and 40 of potash, derived from muriates, 
would be a fair dressing on soils of good character. On 
the poorer soils, the application of the constituents of the 
same kind and forms should be very largely increased. 

In these crops, as in those already mentioned, it is es- 
sential — and success depends upon this as much as upon 
any other factor — that the growth should be continuous ; 
and in order that there shall be no delay in this respect, 
there must be an abundance of available food always at 
their command. 

TUBER CROPS 

In many sections the potato and sweet potato are 
grown for roughage. For these crops no different fer- 
tilization is recommended than that already outlined 
(Chapter XIII) for the crops when grown for market, 
though in the case of sweet potatoes, soils not adapted 
for the growth of marketable tubers may be used. 



CHAPTER XV 
MARKET-GARDEN CROPS 

A knowledge of the principles of plant nutrition is 
perhaps more serviceable in market-gardening than in 
any other line of farming. This branch of farming cannot 
be profitably conducted either without suitable soils or 
without an abundant supply of plant-food. Both of 
these conditions are essential for the growth of high-class 
products. 

THE YIELD AND QUALITY DEPENDENT UPON CONTINUOUS 
AND RAPID GROWTH 

In these days, it is not only the yield of a definite area 
that must be considered, but the edible quality of the 
products that are put upon the market. Quality depends 
upon, or is measured by, both appearance and palata- 
bility; and palatability is determined by the succulence 
and sweetness of the vegetable, or its freedom from bitter- 
ness, stringiness, and other undesirable characteristics 
which frequently exist, and which can be largely eliminated 
provided the grower is thoroughly familiar with his busi- 
ness, assuming, of course, that varieties are the same in 
each case. It has been demonstrated that market-garden 
crops of the best quality are those which are grown under 
conditions which permit of a continuous and rapid develop- 
ment. Any delay in the growth of a radish or of lettuce 

283 



284 



Fertilizers 



is largely responsible for the sharp taste and pungent 
flavor of the former, and the bitterness and toughened 
fiber of the latter. The same principles hold true of early 
table beets and turnips. The beets become stringy and 
wiry in character, and are less palatable if during the 
period of normal growth there has been any delay. In 
a time during which there has been no progress the 




Fig. 26. — Garden Fertilizer Sower. 

The garden fertilizer sower has the advantage of concentrating plant- 
food in the row. This machine is very useful when several small appli- 
cations of soluble constituents are made to young plants during the 
growing season, because it places the plant-food within immediate reach of 
the roots. 

fibrous portion of the vegetable is toughened, and exists 
in too great proportion. In the case of the early tur- 
nip, if any delay in growth occurs, the quality is in- 
jured, and the peculiar, pleasant flavor, a characteristic 
of the perfect vegetable, is changed ; it becomes un- 
pleasant. The unfavorable conditions of growth seem 
to cause more or less reversion to the character of the 
original plant from which the improved type has been 



Market-Garden Crops 285 

derived, mainly through selection and improved methods 
of cultivation. 

All these conditions of growth are not absolutely under 
the control of the grower ; as, for example, a lack of suffi- 
cient moisture and sunshine, the latter of which is cer- 
tainly beyond his power to control. But given good 
natural conditions in respect to soil, and a favorable 
season, the one thing that more than any other controls 
the yield and quality of market-garden products is plant- 
food of the right amount and kind. In other words, in 
crops of this sort, any limitation in this respect usually 
results in a disproportionate reduction in profits. Only 
under exceptional circumstances is it economical to depend 
upon natural soil conditions for profitable crops, however 
favorable such conditions may be, because in successful 
practice the cropping is in the highest degree "intensive," 
and even the best soils are liable to be deficient in some 
essential feature. 

In market-gardening, two factors are essential : first, 
a soil that is capable of absorbing and holding water, 
without being so compact and tight as to prevent free 
movement of water in all directions. Probably a typical 
garden soil would be a sandy loam ; this kind of soil, 
however, would be largely regarded as a good place for 
the plants to grow, rather than as an entire source of food 
required. Hence, the second factor is that the soil should 
contain an abundant supply of all kinds and forms of 
plant-food needed. This may be accomplished by the use 
of manures, preferably well rotted, which contain plant- 
food in more or less soluble forms, but which possess, in 
addition, decaying vegetable matter, so important in con- 
tributing to the physical character of soils, more especially 
in the matter of holding moisture. Hence, any soil well 



286 Fertilizers 

adapted naturally for market-gardening should either be 
heavily manured, or should have been subjected to green- 
manuring for a sufficient period of time to build it up in 
vegetable matter. Owing to the cost, both in money and 
labor, of supplying the food requirements through the use 
of manures only, nowadays resort is made to commercial 
fertilizers; these not only supply the total food, but 
are capable of supplying them in such forms as to enable 
the plants to absorb them at once. That is, there is no 
necessity for any delay, in order that the plant-food con- 
stituents themselves may be made available. Fertilizers 
are therefore capable of supplying the needed require- 
ments when other conditions are favorable, and may be 
grouped into three classes ; i.e. general, specific and 
basic. That is, a general formula would be one that is 
not made for any specific crop, but which contains both 
soluble and insoluble forms of plant-food, with the idea 
of building up the soil in the constituents, rather than 
meeting the special requirements of any one crop. 

The specific formula is one made up for the purpose of 
meeting a particular need of the crop at a particular time. 
These will be noted through the discussions of the various 
crops. A basic formula is one containing large quantities 
of all of the best forms of plant-food to be used as a base 
for supplying market-garden crops with their general 
needs, with the idea that amendments may be made of 
nitrogen, or of other constituents, as the conditions seem 
to require. 

It might seem from the discussion thus far that for 
these crops the recommendations as to methods of fertili- 
zation might be briefly though fully expressed as follows : 

Apply a reasonable excess of all of the essential fertilizer 
constituents to all of the crops. Nevertheless, because of 



Market-Garden Crops 287 

the peculiarities of growth of the different plants, as well 
as the different objects of their growth, distinctions should 
be made in reference to the kinds and amounts of plant- 
food applied, and these distinctions should be borne in 
mind, in order that the most profitable returns may be 
secured. Market-garden crops may, however, be grouped 
according to similarity, both in character and object of 
growth, and each group fertilized in a similar manner, 
which obviates the necessity of extra labor in the prepara- 
tion of fertilizers. 

A basic fertilizer for market-garden crops. 

A good basic fertilizer for market-garden crops may 
consist of : 

Nitrate of soda 250 lb. 

Ammonium sulphate 100 lb. 

Dried blood 150 lb. 

Ground fish 100 1b. 

Acid phosphate, 16% A.P.A 1000 lb. 

Sulfate of potash 400 lb. 

A mixture of these materials of standard quality would 
show an average composition of 4 per cent nitrogen, 8 per 
cent phosphoric acid and 10 per cent potash. Such a 
mixture is an excellent basic formula for such crops as 
asparagus, cucumbers, onions, cabbage, cauliflower, celery, 
eggplant, melons, peppers, squashes and the like, but any 
mixture of the composition 4-8-10 which supplies the 
plant-food constituents in good forms may be used as a 
basic formula for all market-garden crops, leaving the 
specific needs of the different plants to be met by top- 
dressings, or applications of the other constituents. The 
fertilizer ingredients, nitrogen and phosphoric acid, should 
preferably consist of the different forms, rather than to 



288 



Fertilizers 



be all of one form, though the cost of the element will 
naturally regulate this point to some extent. That is, a 
part of the nitrogen should be nitrate or ammonia, and a 
part organic; a part of the phosphoric acid should be 
soluble (from superphosphates), and a part insoluble (from 
ground bone, tankage or natural phosphates). The solu- 




^ „ . , i 





Fig. 27. — Garden Fertilizer Sower with Hoe to work 
Fertilizer into Surface Soil. 

ble portions of both nitrogen and phosphoric acid con- 
tribute to the immediate needs of the plant, and the less 
soluble to its continuous and steady growth, and to the 
potential fertility of the soil. 

The different kinds of vegetables. 

As previously stated, distinctions should be made in 
reference to the kinds and amounts of plant-food applied 
to the many different vegetables. It is impossible in a 
discussion of this nature to give specific directions of the 
details of fertilization of each vegetable ; hence, the dis- 



Market-Garden Crops 289 

eussion following will give consideration to the various 
groups of edible plants as outlined by L. H. Bailey, and 
as much detail concerning each plant as is practicable. 
This grouping is an excellent one because it is based upon 
the object of growth, which is an important factor in the 
cultural methods and fertilization of the various vege- 
tables. 

ROOT CROPS 

Beets and turnips. 

The early table beet and the early turnip are very im- 
portant market-garden crops. Wherever grown, whether 
in the South for the northern market, or in the middle 
states for the near-by market, earliness is a primary con- 
sideration; and the earliness of the crop is determined 
largely by the amount and availability of the nitrogen 
and phosphoric acid applied. These are the two elements 
which, more than any others, modify and dominate the 
growth of these plants, and contribute to their profitable 
production as early market-garden crops. In the case of 
early turnips particularly, a difference of two or three 
days in the beginning of the harvest will often determine 
the profit or loss upon the crop. The experience of many 
growers confirms the view that for no other crop is the 
necessity for right fertilization more important. Since 
the early growth of these crops takes place before active 
nitrification begins in the soil, dependence for this element 
must be placed upon the nitrogen applied, and it is desir- 
able not only that the soils should be well supplied at the 
time of planting with all of the constituents, but that fre- 
quent top-dressings of the soluble nitrate shall be made. 
Top-dressings are recommended because the application 
of a sufficient amount of the nitrogen in this form at the 



290 Fertilizers 

time of seeding might result in its considerable loss, since 
at this season rains often occur which are frequently so 
heavy as to cause a leaching of the nitrates into the drains 
or into the lower layers, and thus prevent the continuous 
feeding of the plant, and a consequent delay in growth. 

An application, therefore, of from 1000 to 1500 pounds 
of a high-grade fertilizer, one of the composition of the 
basic fertilizer already suggested (p. 287), is frequently 
employed at the time of seeding, followed by a top- 
dressing of from 50 to 100 pounds of nitrate of soda to 
the acre once every week or ten days, for at least three or 
four weeks after the plants have well started. It will 
meet the requirements for added fertility. Such a prac- 
tice, under average seasonal conditions, insures a con- 
tinuous and rapid growth, and obviates to some extent 
the dangers liable to follow from too much rain or from 
drought. The frequent applications prevent losses from 
leaching if heavy rains follow, and, except in case of exces- 
sive and prolonged drought, the nitrate remains in solu- 
tion, and is ready to be immediately absorbed by the 
plant. The advantage of earliness which is gained by the 
use of apparently excessive amounts of nitrogen is two- 
fold : a higher price is received for the product, and the 
cost of labor required for each unit of income is less. 
Quite as large yields may be obtained by smaller dressings, 
but the net income is reduced as the time necessary for 
the growth of a marketable beet or turnip is increased. 
See also Chapter XIV, in reference to this subject. 

Carrots. 

The food requirements of carrots are very great, a 
yield of 15 tons an acre will remove 48 pounds of nitrogen, 
27 of phosphoric acid and 153 of potash. For high-grade 



Market-Garden Crops 291 

edible carrots, no less than 1000 pounds of a mixture 
carrying 4 per cent of nitrogen, 4 per cent of phosphoric 
acid and 12 per cent of potash should be used. In case 
the season is favorable for rapid development, top-dressings 
of nitrate of soda are very profitable. 

The other crops of this group, including celeriac, chicory, 
horseradish, parsnip, radish and salsify, may be fertilized 
with liberal applications of the basic fertilizer. It should 
be remembered in connection with each that the crops of 
this group require large quantities of potash, and that 
phosphoric acid is relatively much less important. 

BULB CROPS 

This group includes chive, garlic, leek, shallot and 
onion. Because the onion is the most important it is 
discussed liberally. The fertilization of the other crops 
may be the same. 

The growing of onions, either from seed or from sets, 
and the growing of sets according to "intensive" systems 
of practice, requires a soil of a suitable physical character 
well supplied with all of the essential constituents of fer- 
tility. The minerals should be supplied in abundance by 
superphosphates and potash salts, while the nitrogen 
should be supplied in the most active forms, and in even 
larger amounts than for many other crops. The present 
systems of growing these crops require that the sets shall 
be planted and the seed sown more thickly than was 
formerly believed to be desirable, which permits of a 
larger yield to the unit of area, though it requires better 
culture and a very much larger quantity of available plant- 
food than was the case under the former rather "exten- 
sive" systems of culture. Except in the case of very 



292 Fertilizers 

early onion crops, immediate rapid growth after setting 
is not so essential as in the case of many other market- 
garden crops, and in the growing of onion sets, when the 
soil is richly provided with food, great care in manage- 
ment is necessary in order to secure a development of bulb 
that shall not be too large, in which case the salable 
quality of sets will be reduced. Hence, to avoid this, 
the seed should be spread thickly, in rows about 3 inches 
wide, and the cultivable portion between the rows about 
8 inches wide. With so large a portion of the surface area 
occupied with the crop, the danger of too large develop- 
ment from heavy fertilization is greatly reduced. 

In growing scallions, the soil should not only be richly 
provided with minerals and organic forms of nitrogen, as 
in the case of the other, but should be supplied early with 
soluble nitrate, in order to meet the demands for this ele- 
ment before it is available from soil sources. In the grow- 
ing of crops which require so much hand labor as onions, 
fertilizers are also preferable to yard manures, because 
they are free from weed seed. Further, fertilizers do not 
contribute toward the development of insects or diseases, 
as is sometimes the case with manures, particularly with 
the product derived from city stables. 

A good general fertilizer for onion sets for soils of fair 
fertility may consist of about 50 pounds to the acre of 
nitrogen in organic forms, as dried blood, cotton-seed meal 
or tankage, 60 of phosphoric acid, which may be partly 
in organic forms, as bone or tankage, and 100 of actual 
potash, derived from a muriate. The application of a 
formula containing — 

Nitrogen 5% 

Phosphoric acid 6% 

Potash 10% 



Market-Garden Crops 293 

at the rate of 1000 pounds to the acre, and well worked 
into the soil previous to planting, would furnish these 
amounts, and this application, together with a top- 
dressing of from 75 to 100 pounds to the acre of nitrate 
of soda, or 60 to 75 pounds of sulfate of ammonia, two or 
three times at intervals of about three weeks, the first 
after the crops have well started, would provide not only 
an abundance of food of the right sort, but the nitrogen 
when needed, without danger of loss. 

If the soil has been well dressed with a general fertilizer, 
as above described, the scallions should receive a dress- 
ing of nitrate just as soon as growth begins in the spring, 
as rapid and early growth at this season will, other con- 
ditions being equal, depend upon the supply of available 
nitrogen, and nitrogen in available forms is not usually 
present in the soil in sufficient quantities so early in the 
season. 

COLE CROPS 

Broccoli, brussel sprouts, cabbage (see Fig. 28, Plate 
XIV), collard, cauliflower and kale are all large-leaved 
plants and voracious feeders, and are specifically benefited 
by large applications of nitrogen and of phosphoric acid. 
Heavy applications of the basic fertilizer, which is excel- 
lent, should be supplemented upon good soils with addi- 
tions of nitrogen and phosphoric acid, and upon light 
soils, potash may also be added. Notwithstanding the 
fact that these crops are particularly benefited by nitro- 
gen, the character of the edible portion or head of the 
different plants is very largely influenced by the nature 
of the growth. Too rapid an early growth, due to an 
excess of nitrogen, frequently results in an abnormal 
development of leaf, which is not accompanied by a 



294 Fertilizers 

proper formation of the head ; hence a part of the nitro- 
gen essential for the growth of the plant after the 
head has begun to form should be applied at this time 
in an immediately available form, and a part in forms 
which will gradually feed the plant. A good method of 
fertilization, in addition to the application of from 1000 
to 1500 pounds to the acre of the basic fertilizer, there- 
fore, may consist of a top-dressing of 100 pounds of nitrate 
of soda and 200 of superphosphate to the acre, after the 
plants have begun to make growth after transplanting. 
After the heads begin to form, another top-dressing of 
200 pounds of nitrate of soda may be applied, which will 
contribute toward a rapid and continuous growth of head, 
provided an abundance of the minerals is present, as 
already indicated. 

A number of crops belonging to this group of plants 
require, in addition to a sufficient supply of plant-food, 
peculiar climatic conditions for their best crop develop- 
ment. Cauliflower, particularly, not only seems to be so 
influenced, but great skill and experience are required on 
the part of the grower. It must be remembered that 
while proper fertilization is essential, it is only one of the 
primary conditions of successful culture. 

POT HERBS 

Beet, chard, dandelion, mustard, sea kale and spinach, 
grown for their tops or the edible portion of the leaf, are 
encouraged in their development by an abundance of 
available nitrogen, as this element is the one which con- 
tributes more than any other to formation of leaf. Abun- 
dant growth of the right sort is only accomplished when it 
is present in such quantities and in such forms as to con- 



PLATE XIV. — Cabbage and Watermelons. 




Fig. 28. — Cabbage Heavily Fertilized, Freehold, New Jersey. 




Fig. 29. — Watermelons, Peppers and Corn Fertilized with Basic 
Fertilizer, Clarksboro, New Jersey. 



Market-Garden Crops 295 

tinuously supply the plant with its needs. Reasonably 
heavy dressings of the basic formula, 1000 pounds to the 
acre, or over, at time of planting, should be followed by 
a top-dressing of 100 pounds to the acre of nitrate of soda 
after the plants are well started. The late fall and winter 
growth of spinach is especially benefited by the application 
of nitrates. 

SALAD CROPS 

Celery. 

Celery is another plant that luxuriates in a soil rich in 
vegetable matter, though the peculiar advantage of this 
natural condition of soil may be largely met where it is 
possible to secure an abundance of water and plant-food 
in soluble forms. In the absence of an abundance of 
water, even the best judgment in application of fertilizers 
will not result in satisfactory growth. A heavy applica- 
tion of the basic mixture — a ton to the acre, used at time 
of setting the plants — may be followed with advantage 
by frequent and reasonably heavy top-dressings of nitrate 
of soda, 100 pounds to the acre or more, and well worked 
into the soil. This abundance of soluble nitrogen will 
contribute toward that rapidity of growth which is accom- 
panied by the peculiar crispness and sweetness that gives 
edible quality to this vegetable. In the absence of suffi- 
cient water and food, not only is the growth of the plant 
retarded, but the quality of that obtained is materially 
influenced, since the development of the bitter flavor and 
fibrous character that frequently cause a reduced consump- 
tion of this valuable plant is apparently encouraged. 

What has already been said concerning this vegetable 
is true of a number of others : the main thing is to see to 
it that such an abundance of available food of the right 



296 Fertilizers 

kind is provided as to make possible a rapid growth when 
other conditions are favorable. This is one of the pri- 
mary necessities, if a high yield of good quality product is 
obtained. 

Lettuce. 

There is no market-garden crop which derives greater 
benefit from heavy applications of stable manure than 
lettuce. Besides increasing the amount of plant-food in 
the soil, it helps to bring about that mechanical condition 
of soil so important in successful lettuce-production. 
Crispness and high quality are essential to make lettuce 
readily marketable, hence an abundance of all the con- 
stituents of plant-food in available form must be present 
in the soil. An application of no less than 1000 pounds 
of the basic mixture should be used at the time of plant- 
ing, supplemented with dressings of nitrate of soda at the 
rate 100 to 150 pounds to the acre at intervals of ten to 
fifteen days after the plants are of fair size. 

The fertilization of corn salad, cress, endive and parsley, 
the other plants of this group, may be essentially the 
same as that suggested for lettuce. They are all grown 
for the leaves and require fertile soils liberally supplied 
with all the constituents of plant-food in available forms. 

PULSE CROPS 

Peas and beans of the various kinds and varieties belong 
to the legume family, and possess the power of acquiring 
nitrogen from the air; they are, therefore, ordinarily 
placed in a separate class in respect to their fertiliza- 
tion with nitrogen. When they are grown as market- 
garden crops, however, it is frequently the wiser economy 



Market-Garden Crops 297 

to apply nitrogen, particularly if they are raised upon 
land which has not been previously planted with these 
crops, and thus may not possess the specific nitrogen- 
gathering bacteria : because it is imperative that the 
plants should not only have an abundance of all of the 
food constituents, but that their food should be such as 
to cause as long a cropping period as possible, and nitro- 
gen will contribute to this end. Hence, in the fertiliza- 
tion of these crops, while the minerals are the primary 
constituents needed, nitrogen should also be applied, and 
it should preferably be in the organic forms, which en- 
courage a longer period of growth, rather than in the 
single, active-form nitrate, more generally recommended 
for the quick-growing market-garden crops, because its 
complete solubility and immediate availability encourage 
a rapid growth and short period of development. The 
basic fertilizer recommended, if applied at the rate of 500 
to 600 pounds to the acre, will usually furnish sufficient 
nitrogen, and may, if necessary, be supplemented by the 
application of amounts of superphosphate and potash 
salts which will add from 20 to 30 pounds of phosphoric 
acid, and 60 to 75 of potash. 



SOLANACEOUS CROPS 

Eggplant. 

The eggplant belongs to the same botanical family as 
the potato, and while specifically benefited by the fertiliz- 
ers recommended for that crop, is improved by the 
further addition of nitrogen, which stimulates an early 
leaf growth. Good organic forms are quite as useful as 
the nitrates or ammonia, unless the latter are used fre- 
quently as top-dressings. (See page 239.) 



298 Fertilizers 

Peppers. (See Fig. 29, Plate XIV.) 

The same treatment may be accorded peppers when 
grown under garden conditions as previously suggested on 
page 257, except that a more liberal supply of plant-food 
may be made. It should be remembered, especially in 
connection with liberal applications of stable manure, that 
an abundant supply of minerals should be present in the 
soil to encourage continuous growth and fruiting. After 
the plants are well established, an abundance of available 
nitrogen should be avoided. 

Tomatoes. 

The fertilization of both early and late tomatoes is 
discussed in Chapter XIII, and it seems unnecessary 
to add to that discussion here except to emphasize the 
importance of a liberal supply of the mineral elements 
— phosphoric acid and potash. Many growers have 
found the Wagner system of fertilization, which is based 
upon the necessity of an abundant supply of minerals 
and fractional applications of available nitrogen, a good 
practice. (For Wagner System, see page 205.) On the 
other hand, there are many growers who prefer to make a 
single application in large amount of a fertilizer deriving 
its nitrogen from a number of sources. A mixture very 
generally used in New Jersey is made of the following 
materials : 

Nitrate of soda 100 lb. 

Sulfate of ammonia 100 lb. 

Dried blood, 16% AM 100 lb. 

Ground fish 100 1b. 

Ground bone 100 lb. 

Acid phosphate 1 100 lb. 

Sulfate of potash 400 lb. 



Market-Garden Crops 299 

This is undoubtedly an excellent mixture which may be 
used with safety in almost any quantity. The usual 
practice is to use from 1000 to 1200 pounds to the acre. 
Many farmers claim that the sulfate of ammonia causes 
some injury to the tomato and prefer to double the quan- 
tities of blood and fish used. Whether there is any 
ground for this claim has never been definitely deter- 
mined, but it is known that sulfate of ammonia leaves a 
large residue of acid in the soil. 

VINE CROPS 

Cucumbers, watermelons (see Fig. 29, Plate XIV), musk- 
melons, pumpkins and squashes belong to one botanical 
group of plants, and are usually adapted for similar 
climatic and soil conditions, though watermelons and 
muskmelons of good quality are successfully grown only 
upon light, warm, sandy soils. The pumpkins, cucum- 
bers and squashes may be readily grown to perfection 
upon the colder and more compact clayey soils. All 
of these crops require an abundance of vegetable matter 
in the soil, in order to make their best growth. Hence, 
upon soils deficient in this respect, manures should 
be applied which are rich in vegetable matter. Com- 
posts in the hill have proved of especial advantage, 
as they seem to encourage an immediate feeding, and 
prevent delay in early growth. In the best growth of 
these plants it is also necessary that the mineral ele- 
ments shall be available, and that the nitrogen shall be 
of such a character as to encourage a continuous rather 
than a quick growth of vine. That is, unless the quick- 
acting nitrates are applied very frequently, they are less 
desirable than organic forms of nitrogen. Hence, with the 



300 Fertilizers 

usual broadcast application of the basic mixture at the 
time of planting, together with a compost in the hill, 
further applications of organic nitrogen should be made, 
its character to be such as to promise a relatively rapid 
change into nitrate. The basic mixture may be reen- 
forced by any one of the following materials : 200 to 300 
pounds to the acre of cotton-seed meal, 100 to 200 of 
dried blood or 300 to 400 pounds of fine-ground tankage 
or ground fish. Any organic substance whose greater part 
will decay in one season will generally give better results 
than the nitrate, unless the latter is applied in frequent 
small top-dressings, because organic forms of nitrogen 
provide for a continuous growth of vine and fruit, while 
too great an abundance of immediately available nitrogen 
as nitrate is liable to cause too rapid and large growth of 
fruit of poor quality. This does not apply in the case of 
cucumbers for pickling, where a large setting of immature 
fruits is desired. In this case, nitrogen in the form of a 
nitrate, if properly applied, will contribute to a large 
setting and a rapid growth of the fruits. 



MISCELLANEOUS CROPS 

Asparagus. 

Asparagus is one of the very important vegetable crops, 
and perhaps no other renders so profitable a return for 
proper manuring and fertilizing. It differs from the 
majority of the others in two essential particulars. First, 
it is a perennial, the length of life of a bed depending 
largely upon the treatment; and second, only one crop 
can be obtained in a season — it occupies the land to the 
exclusion of other crops. Hence, special efforts should be 
made to obtain as large a crop as the conditions of season 



Market-Garden Crops 301 

and climate will permit. With this plant the yield and 
market quality of the crops depend upon the number and 
size of the shoots. In respect to quality, the demands of 
the different markets vary. Some of them require that 
the shoots shall be bleached and so cut as to present only 
a green tip, the remainder being perfectly white, while 
others demand that the shoot shall be green. But in both 
cases, the size of the shoot determines salability, and the 
size is largely measured by the methods observed in feed- 
ing the plant when other conditions are favorable ; that 
is, if not injured by disease or insects. Small, spindling 
shoots usually indicate that the crop has not been well 
cared for, or that the plant has been imperfectly nourished. 

The root is enlarged and invigorated by the character 
of the growth of the tops, or summer growth of the plant 
after cutting is finished, and it is obvious that the manur- 
ing should be such as to encourage not only a rapid growth 
of shoots early, but a large and vigorous growth of tops 
later, which assists the growth of the roots in which energy 
is stored up for the production of the crop in the following 
year. Hence, not only the character but the method of 
fertilization is important, and it differs from that recom- 
mended for those plants which grow from the seed in one 
season and which must depend upon what they are able 
to acquire during their short period of growth. 

It was formerly believed that one of the mo6t impor- 
tant ingredients of manures for the asparagus plant was 
common salt, and that in any fertilization this substance 
should occupy a prominent part. Experience has shown, 
however, that while salt may not be harmful, there is no 
real fertility value in it. The crop may be profitably 
grown without its application, though it does no harm, 
and there is no objection to its use except on the ground 



302 Fertilizers 

that it adds no essential fertility element, and its indirect 
benefit may be obtained more cheaply by the use of other 
materials, which contain salt as a normal ingredient, — 
for example, kainit, the crude potash salt, which is one- 
third salt, though its market price is based solely upon its 
potash content. 

Fertilizers which have been found very useful for 
asparagus are those which contain food both in immedi- 
ately available and in gradually available forms. During 
the early growing season, the available food may be 
appropriated rapidly enough to cause an increase in the 
yield of shoots of that year; and inasmuch as the plant 
continues to grow until winter, the food that becomes 
gradually available is appropriated later, and contributes 
to the strength and vigor of the roots upon which the next 
year's crop depends. Furthermore, because the crop is 
gathered from the early shoots, which are continuously 
removed for from one to two months, the root is continu- 
ously drained of its stored-up material, and at the end of 
the cutting season it has been very much reduced in 
vitality; wherefore it is particularly desirable that avail- 
able food be applied at this time also, in order to encour- 
age a rapid and vigorous growth of the top, which aids in 
the storing up of food in the root. A fertilizer containing — 

Nitrogen 4% 

Phosphoric acid 8% 

Potash 10% 

the nitrogen to be drawn from both soluble and organic 
sources, and the phosphoric acid from both superphosphate 
and ground bone, or tankage, and the potash from muriate, 
may be applied at the rate of 1000 to 1500 pounds to the 
acre, and thoroughly worked into the soil at the time of 



Market-Garden Crops 303 

setting the crowns, or even in greater amounts from year 
to year, preferably early in the spring, in order that the 
plant may have the whole season for the appropriation of 
the food. 

The specific fertilizer, in addition, should contain im- 
mediately available forms of food, and should be applied 
preferably immediately after or during the latter period 
of the cutting, in order to feed at once, and thus stimulate 
and strengthen the plant in its condition of lowered vitality, 
due to the continuous and large removal of the shoots. 
This application should also be liberal, since, as already 
indicated, limitations at this time may result in a greatly 
decreased yield and a poorer quality of product the next 
year, and hence a reduction in profit. The best growers 
apply, in addition to the fertilizer recommended, and after 
cutting, not less than 250 pounds of nitrate of soda, 300 
of superphosphate, and muriate of potash, or kainit, 
equivalent to 100 pounds of actual potash. 

These recommendations as to the amounts of fertilizers 
may seem rather large to those who have been accustomed 
to light applications, but they are the minimum rather 
than the maximum amounts, as many growers have learned 
that the extra amounts applied are preferable to the 
smaller amounts, contributing not only to the length of 
life of the plant, but also to the total yield and size of the 
shoots, as well as to their edible quality, which is measured 
by their succulence and flavor. 

These suggestions as to fertilizers are for conditions 
where large amounts of organic or natural manures are 
not readily obtainable. When these are used, they may 
serve instead of the basic fertilizer, but cannot well sub- 
stitute the special applications of artificial fertilizers made 
after cutting is finished. 



304 Fertilizers 

The fertilization suggested above may be used with 
absolute safety and excellent results may be obtained, but 
it should be kept in mind that investigators and growers 
differ greatly regarding the fertilizing of asparagus. 
While it is conceded that nitrogen is the most important 
element, the form and time of application are still matters 
of contention. As an alternative method, Watts makes 
the following suggestions : " If seeds and plants have been 
selected intelligently and all cultural conditions are favor- 
able, the following treatment should give good results : 
Apply 10 to 15 tons of fine manure early in spring, or 
probably with as much benefit immediately after the 
cutting season ; one and one-half tons of a 4-8-10 mixture, 
half applied in early spring, and half immediately after 
the first cutting ; 150 pounds of nitrate of soda by broad- 
casting as soon as growth begins in the spring ; 150 pounds 
of nitrate of soda when the cutting season is half over; 
150 pounds of nitrate of soda at the close of the cutting 
season and the same quantity one month later." 

Rhubarb. 

Rhubarb is a crop somewhat similar to asparagus, in 
that it is a perennial, and that the best fertilization is one 
which not only provides food for the growth of the imme- 
diate crop, but which encourages the growth of top after 
the regular crop is harvested, and thus restores the vitality 
of the plant — which has been weakened by the continu- 
ous removal of the stalk and leaf — and enables it to 
store up energy for the subsequent crop. An annual 
application of 1500 pounds of the basic formula (p. 287) 
early in the spring, preferably plowed in, may be followed 
with advantage by a top-dressing of 150 pounds to the 
acre of nitrate of soda in about two weeks after harvesting 



Market-Garden Crops 305 

has begun, and a similar dressing after harvesting has 
ceased. These dressings should be cultivated into the 
soil, unless immediately followed by rain, which will dis- 
tribute the salt into the lower layers of soil. Plants of 
this sort, from which only one crop can be secured, should 
be stimulated to the largest possible production. 

Sweet corn. 

In the case of sweet corn, the early crop is usually the 
most profitable. The recommendations that are made for 
the fertilization of the field crop do not apply to this, be- 
cause the object is not the matured crop, which makes its 
greatest development in July and August, the most favor- 
able season of growth, but the early green product, which 
is often harvested before the field crop has fairly begun to 
grow. This early and rapid growth, therefore, cannot be 
attained by methods of fertilization suitable for the field 
crop (Chapters XII and XIV) . It can be accomplished only 
when an abundance of the mineral foods is present, and 
when the nitrogen is in part, at least, in forms which may 
be directly absorbed, as much growth must be made pre- 
vious to the time that nitrification takes place in the soil. 

The large quantity of well-rotted manure which, until 
recently, was practically the only manure used for this 
crop, while extremely valuable, can be in part substituted 
by a liberal dressing of the minerals, phosphoric acid and 
potash, and further supplemented by nitrogen in readily 
available forms. The use of 1000 to 1200 pounds of a 
mixture composed of the following ingredients 

Nitrate of soda 200 lb. 

Dried blood, 16% AM 100 lb. 

Ground fish 200 lb. 

Acid phosphate 1200 lb. 

Muriate of potash 300 lb. 

x 



306 Fertilizers 

may be practiced with advantage. Where cotton-seed 
meal may be secured at a reasonable price, it may be used 
instead of fish. This mixture should be supplemented by 
top-dressings of nitrate of soda whenever the plants show 
that more nitrogen is needed. Care should be taken to 
work the nitrate of soda into the soil immediately after 
the application is made. The basic formula (page 287) 
used at the rate of 800 to 1000 pounds to the acre and 
supplemented by top-dressings of nitrate of soda may be 
used with good results if more convenient. 

Okra. 

The production of okra is increasing, especially in the 
canning sections, where it is grown extensively and the 
pods prepared for soup. It requires a warm and fertile 
soil. Because okra is grown for pods while still green and 
which must be crisp and tender, an early and vigorous 
growth of leaf and stem is required. The best practice is 
to use no less than 1000 pounds of a high-grade mixture 
deriving a large part of its nitrogen from nitrate of soda, 
and the remainder from quickly available forms, as blood, 
fish, cotton-seed meal and tankage. Because it continues 
its growth late in fall, tankage, which is less available 
than the other materials, is valuable. The minerals should 
be present in the soil in abundance. Stable manure is 
desirable because it improves the mechanical texture of 
the soil, as well as to supply plant-food. 

CONDIMENTAL OR SWEET HERBS 

There is a large number of sweet herbs common to 
European gardeners but of little commercial importance 
in this country. It is not uncommon, however, to find 



Market-Garden Crops 307 

one or more of these plants in most any American garden. 
The fertilization of these crops, including dill, mint, sage, 
savory, thyme and tansy, is in large degree dependent 
upon the object of their use, that is, whether for leaf 
or seed. In general, they require a warm soil well sup- 
plied with all the elements of plant-food. A liberal 
application of manure and 1000 pounds of the basic 
fertilizer should be sufficient. 

In all of the suggestions made as to the fertilization of 
market-garden crops, not only has the question of yield 
been kept in mind, but also the quality of the product, 
which is a measure of salability. The question is often 
raised as to whether the forcing of these crops by means 
of active fertilizers may not result in too coarse and one- 
sided a growth. Such growth does frequently follow a 
heavy fertilization with nitrogen, if accompanied by too 
light a fertilization with minerals. The tendency of the 
plant is to make a normal development when a sufficiency 
of all of the fertility elements are present, but in these 
crops the object is really a one-sided growth in many 
cases, since that growth is usually better adapted for the 
purpose than that obtained under what may be regarded 
as normal conditions. It must be remembered, too, in 
the growing of certain vegetables, such as radishes, celery, 
etc., or those in which the roots are the edible portion, 
that commercial fertilizers do not contribute any undesir- 
able flavors. In fact, they are often largely responsible 
for those peculiar characteristics which give quality; 
whereas, when these vegetables are grown by the exclu- 
sive and necessarily excessive applications — if large 
yields are to be secured — of natural manures, undesir- 
able qualities are frequently contributed by them. 



CHAPTER XVI 
ORCHARD FRUITS AND BERRIES 

It is not until within recent years that the question of 
manuring or fertilizing fruit trees and berries has come to 
be of particular interest. This is due primarily to the 
fact that demands for fruit and berries have been relatively 
limited as compared with the staple crops. Hence, fruit- 
growing as a business, or on a commercial scale, is compara- 
tively new, though the opinion is quite prevalent among 
fruit-growers that trees, particularly, are indigenous to 
most soils, and grow freely like weeds, and that therefore 
orchard crops are not as exhaustive of the fertility elements 
as others. They cite, as an argument on this point, the 
fact that lands from which timber has been recently 
removed are much more productive than those upon which 
many regular farm crops have been grown. Scientific 
investigation and practical experience, however, teach that 
forest growth and fruit growth are quite different in respect 
to the needs of fertilizing elements, and that progressive 
fruit-culture demands that quite as much attention shall 
be given to the matter of providing proper plant-food as is 
now known to be desirable for the other and more common 
crops of the farm grown for profit. 

FRUIT CROPS DIFFER FROM GENERAL FARM CROPS 

It is obvious that suggestions as to the character of the 
fertilizing of the cereal crops, grasses and vegetables, 
must be somewhat different from these fruits, because the 

308 



Orchard Fruits and Berries 309 

former differ from the latter not only in their habits of 
growth, but in the character and composition of the crop 
produced, and in their relation to soil exhaustion. General 
farm crops, with few exceptions, require but one year for 
the entire processes of vegetation and maturation. Fruit 
crops, as a rule, require a preparatory period of growth of 
tree or bush before any crop is produced, which is longer 
or shorter according to the kind of fruit. Furthermore, 
after the fruit-bearing period begins, the vegetative proc- 
esses do not cease, but are coincident with the growth and 
ripening of the fruit. The crop product, or the fruit, also 
differs materially in its character from the general farm 
crop, or from vegetables, which reach their harvesting 
stage and die in one season, because for many kinds a whole 
season is required for growth and development. 

That is, in fruit-growing it is necessary that there shall 
be a constant transfer of the nutritive juices from the tree 
to the fruit throughout the entire growing season, while 
the growth for each succeeding year of both tree and fruit 
is dependent upon the nutrition stored up in buds and 
branches, as well as upon that which may be derived 
directly from the soil. 

" In the next place, the relation of fruit-growing to soil 
exhaustion is very different from that in general-crop 
farming, because in orchards there is an annual demand 
for specific kinds and definite proportions of soil constitu- 
ents. It is really a continuous cropping of the same kind, 
and there is no opportunity, as in the case of ordinary farm 
crops, to correct the tendency to exhaustion by a frequent 
change of crops, or the frequent growth of those which 
require different kinds and amounts of plant-food con- 
stituents." * 

1 Voorhees, "Manuring Orchards." Lecture before Massa- 
chusetts Horticultural Society, 1896. 



310 Fertilizers 

THE SPECIFIC FUNCTIONS OF THE ESSENTIAL FERTILIZING 
CONSTITUENTS 

It must be admitted, however, that the general principles 
of manuring, as applied to farm crops, also apply to fruit 
and berry crops ; that is, the essential manurial constitu- 
ents must be the same. 

"A fruit tree will not make normal growth in a soil 
destitute of nitrogen. That nitrogen encourages leaf 
growth is a recognized fact, and since trees grow by means 
of both leaf and root, its presence is required in the soil in 
order to promote the growth and extend the life of the 
tree. It is very evident, too, that potash is an essential 
constituent in the growth of fruits, not only because it 
constitutes a large proportion of the ash of the wood of 
the apple, pear, cheery and plum, and more than 50 per 
cent of the ash of fruit, but because it forms the base of 
the well-known fruit acids. Phosphoric acid is also very 
essential in order to nourish a tree properly, as well as to 
insure proper ripening, though it is apparent from such 
investigations as have been made that this constituent is 
relatively of less importance than for the cereals." 

It is also a matter of common observation that in the 
production of stone-fruits, particularly, lime is an impor- 
tant constituent. Its functions seem to be to strengthen 
the stems and woody portion of the tree, to shorten the 
period of growth, and to hasten the time of ripening. 
Fruit trees growing on soils rich in lime show a stocky, 
steady, vigorous growth, and the fruit ripens well, while 
those on soils which contain but little lime, particularly 
the clays, appear to have an extended period of growth, 
the result of which is that the wood does not mature and 
the fruit does not ripen properly. 



Orchard Fruits and Berries 311 



THE CHARACTER OF SOIL AN IMPORTANT CONSIDERATION 

Soils which possess good mechanical condition, are rich 
in the essential constituents, — nitrogen, phosphoric acid 
and potash, — contain a good proportion of lime and are 
well drained and cultivated, are naturally well adapted for 
fruit trees, as well as for other crops, and the exhaustion of 
such soils will not become apparent for a long time. But 
soils of this character are the exception rather than the 
rule, and the growth of fruit on those which possess the 
opposite characteristics cannot be continued for any con- 
siderable period without an artificial supply of the fertility 
elements. In fact, it is doubtful whether it ever pays to 
attempt to grow fruits on soils of the latter character with- 
out supplying them with an abundance of the essential 
fertilizer elements. 

In the matter of berries, which are crops especially well 
adapted to soils which possess a light, open character, but 
which are not naturally supplied with the essential plant- 
food constituents, proper manuring becomes of even more 
importance than for the tree fruits; though, because of 
their shorter period of life, one or two good crops may be 
secured without heavy fertilization. 

On the whole, however, for all of these crops the great 
need at the present time is for a larger use of fertilizing 
materials, not only because a larger yield may be obtained 
thereby, but because the quality of the product is far supe- 
rior to that grown under conditions which are not perfect in 
this respect. Quality, which is determined by size and 
appearance, is, other things being equal, largely dependent 
upon an abundant supply of plant-food. It is manifestly 
impossible to include all fruit and berry crops in one general 
group, though possessing points of resemblance, because 



312 Fertilizers 

the different ones vary more or less in their character. 
The trees of certain of them are long-lived, — 40 years or 
more, — while others are comparatively short-lived — 
10 years or less. In certain of them the cropping period 
is short ; the fruit ripens at once, while in others the ripen- 
ing period extends over a considerable time. They also 
differ in reference to their demands for plant-food, certain 
of them requiring an abundance of available food, while 
others can readily absorb the food necessary for their 
growth from relatively insoluble compounds. In the 
discussion, similar recommendations may be made in 
many cases, though it is desirable that each class of fruits 
shall be considered separately, and also that distinctions 
should be made between what are regarded as good soils, 
as medium soils and as poor soils, in respect to their content 
of plant-food. 

THE GENERAL CHARACTER OF THE FERTILIZING 

It must be borne in mind, also, that inasmuch as the fruit 
crop is not derived from annual plants, but from perennials, 
the character of the feeding may be very different from 
that in which the entire plant serves as a crop, as is the 
case with the cereals and most vegetables. Hence, the 
fertilizers applied need not all be of such a character as to 
be immediately available. That is, the fertilizing mate- 
rials may be such as to provide for a gradual and continuous 
feeding. Those forms which decay relatively slowly are, 
perhaps, quite as good, if not better, for many kinds of 
fruits than those which by virtue of their solubility and 
immediate availability are more stimulative in their char- 
acter. Those fertilizers which do not contribute to the 
immediate feeding of the tree or plant, but rather add to 



Orchard Fruits and Berries 313 

the reserves of potential plant-food in the soil, should, 
however, in many cases be supplemented by those which 
act more quickly, in order to supply an abundance of avail- 
able food at special times and seasons. In general, there- 
fore, a basic formula, the chief claim of which is that it 
furnishes large percentages rather than specific propor- 
tions or forms of plant-food, may be more reasonably 
adopted for fruits and berries than for other crops, be- 
cause it may be applied with advantage to all of the 
fruits, the amounts to be applied to be adjusted to meet 
the requirements of the different kinds of crop and the 
different kinds of soil. Fertilizers which have been 
found to be very serviceable for fruit crops have been 
made according to the following formulas^ the materials 
of which are familiar to all, and may be readily obtained 
from dealers : (1) One part, or 100 pounds each, of 
ground bone, acid phosphate and muriate of potash ; or 
(2) a mixture of one and one-half parts, or 150 pounds, 
of ground bone, and one part, or 100 pounds, of muri- 
ate of potash ; the mixture of either to be applied in all 
cases. For fruit trees on soils of good natural charac- 
ter, further additions of more active forms of the va- 
rious constituents may not be needed, while on light 
soils, or those of a medium character, or for berries, 
they should be added. 

The chief point to observe is that an excess of nitrogen 
must be avoided, and that if this element is applied in 
active forms, it should be used at such times as to enable 
the plant to appropriate it early in the season, and thus 
become assimilated before the beginning of winter, the 
danger from too great an excess of nitrogenous fertilizers 
being that it causes a too rapid growth of both wood and 
fruit, which do not ripen well. 



314 Fertilizers 

THE APPLICATION OF FERTILIZERS FOR FRUITS 

A point which should be carefully observed in the fer- 
tilizing of orchards is the method of application. The 
fertilizers should, as far as possible, be distributed through- 
out the lower layers of soil, where the feeding roots are 
located. If applied wholly on the surface of the soil, the 
tendency of the root is to go to that point, or where the 
food is, and trees which have the larger proportion of the 
feeding roots near the surface are more liable to surfer 
from drought than those which have them distributed at 
greater depths in the soil. Hence, in the application of 
fertilizers to orchards, particularly in the early life of the 
trees, they should, as far as possible, be well worked into 
the soil, which may be readily accomplished by applying 
upon the surface before plowing. The after-fertilizing, if 
it seems desirable to leave the orchard in sod, may be 
upon the surface, though in that case the soluble fertilizers 
are preferable, since they would rapidly descend, while the 
insoluble would do so more slowly, or only as rapidly as 
they became soluble. 

THE FERTILIZING OF APPLES AND PEARS 

The necessity for the application of fertilizers in the 
growing of apples and pears is largely due to the fact that 
it is really a continuous cropping of the same kind, and 
therefore more exhaustive than a cropping which removes 
more plant-food in the same period of time. While upon 
good soils the trees may be able to acquire sufficient food 
to mature maximum crops for a considerable period, the 
life of the tree, as well as the character of the fruitage, will 
be very favorably influenced by the fertilization. 



Orchard Fruits and Berries 315 

An experiment 1 bearing upon this point is very instruc- 
tive, as indicating the need of manures for fruit trees, not 
only in reference to the amount removed, but also in refer- 
ence to the proportions of the essential constituents re- 
quired. This study shows that the plant-food contained 
in 20 crops of apples, of 15 bushels to the tree, and 35 
trees to the acre, and in the leaves for the same period, 
amounts, in round numbers, to 1337 pounds of nitrogen, 
310 of phosphoric acid and 1895 of potash. These 
amounts of plant-food are compared with the amounts that 
would be removed by 20 years' continuous cropping with 
wheat, assuming an average yield of 15 bushels of wheat 
to the acre, and 7 pounds of straw to 3 bushels of grain ; 
viz., 660 pounds of nitrogen, 211 of phosphoric acid and 
324 of potash. By this comparison it is shown that the 
20 crops of apples remove more than twice as much nitro- 
gen, half as much again of phosphoric acid and nearly 
three times as much potash as the 20 crops of wheat. 

These results are valuable in indicating the rate of soil 
exhaustion by apple-growing. It is to be remembered, 
however, that the larger root development of the tree 
would enable it to draw its nourishment from a larger 
area of soil than is the case with wheat, and thus probably 
permit of normal growth for a longer period. 

Too many are satisfied with short crops of medium fruit, 
with off-years and with short-lived trees, largely because 
they do not know that all of these conditions may be im- 
proved by a proper feeding of the tree, and that such feed- 
ing will usually result in a very largely increased profit. 

Statistics gathered in the state of New Jersey 2 show that 

1 Cornell Exp. Sta., Bulletin No. 103, "Soil Depletion in 
Respect to the Care of Fruit Trees." 

2 Bulletin No. 119, New Jersey Experiment Station. 



316 Fertilizers 

over 90 per cent of the commercial apple-growers in the 
southern and central sections use fertilizers or manures for 
their orchards, whereas, in the northern section about 
70 per cent use manures. In the northern section the 
orchards are usually located upon soils of a very high 
natural strength, and which are peculiarly well adapted 
for the growing of fruits, while in the central and southern 
sections, the soils in many sections are of medium, if not 
of very low, fertility. Hence, while the larger proportion 
of the growers use fertilizers or manures upon the poor 
soils, a very considerable number use manures for orchards 
located upon soils which are regarded as of the best ; yet 
all claim that it is a paying practice. 

There is also a difference in the time at which manuring 
or fertilizing should begin. When the soil is naturally 
good the fertilization need not begin with the setting of the 
tree, as the food obtainable is usually sufficient to provide 
for a good growth of leaf and wood, and in many cases 
maximum crops of fruit for a number of years, though 
even here fertilization should preferably begin as soon as 
large crops are produced, whereas, on the lighter soils, 
fertilization should begin when the tree is set. 

The amounts to be applied. 

For these crops, either of the basic mixtures suggested 
(p. 313) will provide a sufficient proportion of nitrogen, 
except possibly upon the more sandy soil. On light soils, 
the necessity for liberal fertilization with nitrogen is fre- 
quently apparent. In many cases it is possible to obtain 
the necessary nitrogen from the growing of leguminous 
crops, as crimson clover, though when these are used they 
should be plowed down early in the spring, in order that 
their growth may not interfere with the growth of the tree. 



Orchard Fruits and Berries 317 

If they are allowed to remain until mature, they absorb 
not only the food that may be necessary for the growth of 
tree and fruit, but the moisture also, and thus they fre- 
quently injure rather than improve the crop prospects. 

On soils of good natural character, the fertilization of 
apples and pears should begin as soon as the trees reach 
the bearing period, and an annual application of 400 pounds 
to the acre of either formula should be made, preferably in 
early spring, and plowed in. As they grow older and the 
yield of fruit is larger, the amounts should be increased. 
While no definite rules can be laid down as to the most 
profitable amounts to apply, the best growers find that it 
pays to use from 1000 to 1500 pounds annually of mixtures 
which furnish practically the amounts and kinds of plant- 
food contained in the formulas suggested. The profit is 
found, not only in the larger yield, but in the quality of the 
fruit and in the increased tendency toward continuous 
crops, and in longer life of the tree. On soils of medium 
character the fertilization should begin earlier, and the 
amounts of the basic fertilizer should be larger. In many 
cases, too, nitrogen, in addition to that contained in the 
basic formula, should be added, the kind and form de- 
pending, perhaps, upon the relative cost more than upon 
any other one thing, the minimum amount to be 20 pounds 
to the acre, or an equivalent of 125 pounds of nitrate of 
soda. 

On poor soils, the necessity for fertilizing is naturally 
greater than for either of the others. In fact, on these 
liberal fertilization — 500 pounds to the acre of basic 
formula No. 2 — should precede the setting of the trees, 
and be continued annually. On these soils, too, green 
manuring as a source of nitrogen can be practiced with 
safety for a longer period than in the preceding case. In 



318 Fertilizers 

the presence of an abundance of minerals, the need for 
nitrogen is indicated by the color of the foliage. If it 
lacks vigor and is yellow in the spring, rather than green, 
a dressing of from 100 to 150 pounds of nitrate of soda will 
supply the needs to better advantage than any other form. 

PEACHES 

Peaches differ from apples and pears in respect to fertiliz- 
ing because the period of development of the tree, prepara- 
tory to bearing, is shorter, and because the cropping is 
usually much more exhaustive. Hence, the demands for 
added plant-food are proportionately greater in the early 
life of the tree, and are different, because of their more 
rapid growth. That is, forms of nitrogen that are more 
available are preferred to the slowly available materials 
recommended for apples and pears. 

The need of fertilizers. 

The results of an experiment conducted by the New 
Jersey Experiment Station are interesting and valuable, 
as bearing upon this point. They show the value of fer- 
tilization, not only in increasing the yield of crops, but in 
extending the period of life of the trees, and in overcoming 
unfavorable crop conditions. The soil upon which the 
experiment was conducted possessed only medium fertility, 
good mechanical condition, and was fairly representative 
of soils naturally well adapted for peach-growing. The 
fertilized plots received annually — 

Nitrate of soda 150 lb. 

Bone-black superphosphate 350 lb. 

Muriate of potash 150 lb. 



PLATE XV. — Fertilizers for Peaches. 




















JH 


















Wfe 




Ik -- 




?'^ 


fj&M 


j&~ 


?p§|spp 


~ "l 


#^ Mil 


9gi^£ 






fZ 


ZZ-.. 








^^=^s^s 


lffi**v£~"- 








'/ .- 








- vjf" C" - -: 







Figs. 30 and 31. — Views of the Vineland Experimental Peach 
Orchard, New Jersey Experiment Station, Showing (Fig. 30) 
Effect of Nitrogen in Addition to Minerals; Fig. 31, below, 
Minerals Only, No Nitrogen. 



Orchard Fruits and Berries 319 

to the acre, whereas the manured plot received manure 
at the rate of 20 tons to the acre. 

The following tabular statement shows the results 
obtained : 

I. The Yield without Manure 



to the acre 

1884-1891, inclusive, 8 years, average per year . . . 65.7 

1884-1895, inclusive, 10 years, average per year . . . 60.3 

1887-1891, inclusive, 5 crop years, average per year . 105.0 

1887-1893, inclusive, 7 crop years, average per year . 86.2 

II. The Yield with Complete Chemical Manure 

Baskets 
to the acre 

1884-1891, inclusive, 8 years, average per year . . . 164.2 

1884-1893, inclusive, 10 years, average per year . . . 183.4 

1887-1891, inclusive, 5 crop years, average per year . 262.8 

1887-1893, inclusive, 7 crop years, average per year . 262.0 



III. The Yield with Barnyard Manure 

Baskets 
to the acre 

1884-1891, inclusive, 8 years, average per year . . . 169.5 

1884-1893, inclusive, 10 years, average per year . . . 194.7 

1887-1891, inclusive, 5 crop years, average per year . 271.3 

1887-1893, inclusive, 7 crop years, average per year . 276.8 



IV. The Relative Yield in an Unfavorable Season 

Baskets 
to the acre 

1889, unmanured 10.9 

1889, fertilized 152.5 

1889, manured 162.5 



" The first point of importance and value observed is in 
reference to the number of crops that were secured. On 
the unmanured land, the crops secured after eight years 
were so small as to materially reduce the average for the 
whole period, while for the manured land the average for 



320 Fertilizers 

the whole period was not only not reduced, but very materi- 
ally increased ; that is, the crops secured on these after 
the trees on the unmanured land had practically ceased to 
bear were greater proportionately than those secured pre- 
vious to that time. This was true both for the fertilized 
and manured land. 

" In the next place, it is shown that the yield was very 
materially increased by the use of manures, either in the 
form of artificial or natural supplies, and the differences in 
yield derived from these two forms are very slight, indicat- 
ing that very much smaller amounts of actual plant-food 
in quick-acting forms were quite as useful as larger amounts 
of the less available forms in which the food exists in 
natural manure products. 

"For the ten years, the fertilized plot received 250 
pounds of nitrogen, 560 of phosphoric acid and 750 of 
potash, while the yard manure plot received — assuming 
the average composition of yard manure — 2000 pounds 
of nitrogen, 2000 of phosphoric acid and 1600 of potash ; 
yet with eight times as much nitrogen, nearly four times 
as much phosphoric acid and more than twice as much 
potash, the yield was but 113 baskets greater, or an 
average of 11 baskets to the acre. 

" In the third place, it is interesting to observe — and 
it is a point of great importance — the effect of an abun- 
dance of food in overcoming unfavorable weather or sea- 
sonal conditions. The year 1889 was extremely unfavor- 
able, and the crop throughout the state was small. In this 
experiment the unmanured plot yielded at the rate of 10.9 
baskets to the acre, while the manured and fertilized plots 
both showed a yield exceeding 150 baskets to the acre. 
The manure strengthened and stimulated the trees, and 
enabled them to successfully resist such conditions as were 
fatal to the crop on the unmanured land. 



Orchard Fruits and Berries 321 

"This point is one that is seldom considered in cal- 
culating the advantages to be derived from proper manur- 
ing, though it is of extreme value, since the expenses of 
cultivation, trimming and interest on investment are 
quite as great in one case as in the other." 

Methods of fertilizing. 

The peach industry has so extended in the past few years 
that soils of natural high fertility possessing ideal condi- 
tions for peach-production have long ago been utilized. 
The peach crop is no longer a luxury in the farmers' homes, 
but a staple food commodity in all of the markets of the 
country. Many orchards are located on the poorer soils, 
and many more are being planted annually, and this is 
especially true of peaches which may be grown success- 
fully on the lighter types of soils. In order that the health 
and vigor of the trees be maintained it is necessary to 
supply plant-food in abundance. At the same time the 
demand for natural manures, yard and stable manure, has 
increased, and with the advent of motor-drawn vehicles, 
the supply has decreased, leaving the use of commercial 
fertilizers the logical means of supplying the necessary 
food for the tree. 

If commercial fertilizers are to be used efficiently, some- 
thing must be known of the habits of the tree and of the 
kinds and amounts of plant-food required. Good, warm, 
naturally well-drained soils, even though they contain 
relatively small amounts of plant-food, are better adapted 
for peaches than for apples, because the former are shorter 
lived, grow relatively more rapidly and have a relatively 
greater power of acquiring food than the longer-lived 
trees. This statement brings out the character of the tree. 
Work done at the New Jersey Experiment Station, New 



322 Fertilizers 

Brunswick, shows the kinds and amounts of plant-food 
that are needed in order to grow the tree and to make 
mature fruit. " It was shown in that experiment that an 
acre of peaches would require annually after coming to 
the period of bearing, and averaging 2000 baskets of 
peaches to the acre in ten years — 

Nitrogen 71 lb. 

Phosphoric acid 22 lb. 

Potash 48 lb. 

or an equivalent each year of nitrogen equal to 460 lb. of 
nitrate of soda, phosphoric acid equal to 150 lb. of acid 
phosphate and potash equal to 100 lb. of muriate of 
potash." 

At about the same time experiments conducted in Ger- 
many showed the average quantities of nitrogen, phos- 
phoric acid and potash, and lime removed by apples to be — 

Nitrogen 71 lb. 

Phosphoric acid 20 lb. 

Potash 80 1b. 

Lime 95 lb. 

and for pears the quantities removed to the acre were: 

Nitrogen 91 lb. 

Phosphoric acid 18.5 lb. 

Potash 71 lb. 

Lime 120 1b. 

The results confirm in a remarkable manner those 
obtained in this country for peaches, more particularly 
the large amounts of plant-food required annually in the 
growth of these crops. In the German experiments, the 
greater amounts of potash are in all probability due to the 
more liberal supply at the disposal of the German farmers. 
The amount of lime is likewise interesting and remarkable. 



Orchard Fruits and Berries 323 

With these figures in mind, it is obvious that upon soils 
of poor chemical character, but possessing good physical 
condition, much larger amounts would be required than 
upon those soils which are well supplied in this respect, but 
whatever the soil, the tree will need additional food for 
proper growth, assuming, of course, that a part of the food 
necessary is derived from the stores of the soil. Assume 
also that in any case, and more particularly in the case of 
sandy soils, lime should be liberally used, because it is a 
well-known fact that the lime does have a very important 
influence in causing fruiting and encouraging that vigor 
and stockiness of wood growth that is so important. 

The foregoing points very clearly to the need of artificial 
fertilization of peaches. No definite rules can be laid down 
as to the amounts to be applied, and no suggestions made, 
except that the moment a tree is hungry, that moment food 
should be supplied, and the evidence of hunger is so apparent 
in most orchards that much more fertilizer than is now used 
could be applied with very great profit. One should 
remember also that not only is the fertilizer necessary in 
order to feed the plant, but that an ample supply of food 
contributes to the power of the tree to resist insects and 
fungous attacks, to outgrow slight injuries, which would 
result in the absence of proper nourishment in very materi- 
ally injuring the fruit prospects. 

In order that the tree may be fed the moment it is 
hungry, an abundance of plant-food, especially the minerals, 
should be at its command. It is necessary to be more 
careful with the use of nitrogen. It has already been 
mentioned that it is well to have the soil in good condition 
before setting. It is not so necessary with peaches as 
with apples and pears, but it is a good practice to make an 
application of 300 to 500 pounds to the acre of a mixture 



324 Fertilizers 

of equal parts of ground bone, acid phosphate and muriate 
of potash before the trees are planted, especially upon poor 
soils. For later years the following recommendations 
are made, based upon the results of experimental work 
conducted by the New Jersey Experiment Station : 

For young trees — two to three years old, before coming 
into bearing : 

150 lb. muriate of potash] 

300 lb. acid phosphate [to the acre 

100 lb. nitrate of soda J 

For the first and second year of bearing : 

150 lb. nitrate of soda 1 
400 lb. acid phosphate \ to the acre 
100-200 lb. muriate of potash J 

During mature bearing : 

200 lb. nitrate of soda J 

400 lb. acid phosphate \ to the acre 

200 lb. muriate of potash J 

These mixtures are by no means inviolable. Conditions 
modify their use. The character of the growth and yield 
of the trees will be a suitable guide to the application of 
fertilizers. If the yield is poor one year, the application 
of the next spring may be reduced 30 per cent, and also 
where leguminous cover-crops are grown as green-manures, 
the amount of nitrate of soda in the mixture may be re- 
duced 25 per cent. The tree itself will show in its growth 
indications of either proper nourishment or lack of it 
which assist in the management of the orchard. (See Figs. 
30 and 31, Plate XV.) 

Whatever the fertilization, it should be remembered 
that the soil should be abundantly supplied with decaying 



Orchard Fruits and Berries 325 

vegetable matter because this humus-forming material 
assists constantly by improving the physical character 
of the soil and the stores of plant-food, besides lending 
great aid in the conservation and better distribution of 
water, the one factor more than any other which controls 
size and quality of crop. 

Many orchardists use much larger amounts of fertilizer 
than is here recommended, though if the suggestions con- 
cerning the method of use are carried out, the quantities 
named will be found sufficient to supply all the needs of 
maximum crops. 

PLUMS, CHERRIES AND APRICOTS 

The fertilizing of these fruits, when grown on the differ- 
ent classes of soils, need not differ materially from that 
recommended for peaches under the same conditions, 
though cherries, particularly, require in addition to the 
essential constituents, nitrogen, phosphoric acid and pot- 
ash, a relatively greater supply of lime, and this substance 
should be applied in addition to the regular fertilization. 
Care should also be exercised in the application of nitro- 
gen, in order to prevent a too great development of leaf 
and branch. Unless these trees show a decided need for 
nitrogen, a medium application of the second basic formula 
(p. 313) will furnish sufficient for their needs. 

CITROUS FRUITS 

These products — the oranges, lemons and the like — 
belong to a distinct class of fruits, and the experience 
already gained in their fertilization is such as to make 
applicable the suggestions concerning peaches, plums and 
apricots. On the lighter sandy soils of Florida, which are 



326 Fertilizers 

naturally well adapted for oranges, growers have found 
potash to be a specially important element in manures. 
The nitrogen and phosphoric acid should be accompanied 
by a larger proportion of potash than is recommended 
for the stone fruits. Great care should be exercised in the 
use of nitrogen, though in the case of these semi-tropical 
crops the danger from immature growth, as in the case of 
fruits for the more northern climates, is not so marked. 

SMALL-FRUITS 

These crops do not differ from those already discussed 
in reference to their needs for liberal fertilization, yet be- 
cause of their different character of growth, the method of 
fertilization should be somewhat different. They are, as 
a rule, crops which require a shorter preparatory season, and 
have a shorter period of bearing life. The strawberry, 
for example, does not advantageously bear more than two 
crops without resetting, whereas the blackberry and rasp- 
berry may range in life from four to eight years, and the 
gooseberry and currant are relatively long-lived, provided 
they are supplied with an abundance of food. In respect 
to their general character, they correspond more nearly 
with the vegetable crops than with the cereal grains, in 
that they possess a relatively higher market value and a 
lower fertility value than these, and the period of growth 
and development of the fruit is much shorter. Therefore, 
natural sources of plant-food may be largely ignored in 
their growth, and the more quickly available — particu- 
larly nitrogenous and phosphatic — materials supplied. 

Strawberries. 

In the case of the strawberry, the preparatory period 
of growth of the plant before bearing is but one year, and 



Orchard Fruits and Berries 327 

the crop that may be obtained is largely dependent upon 
the strength and vigor of plant which has been acquired 
during this period. Hence, it is desirable that the soil in 
which the plants are set should be abundantly provided 
with the mineral elements, particularly with soluble and 
available phosphoric acid ; hence an application of from 
500 to 800 pounds to the acre of basic formula No. 1 (p. 
313) is recommended. The nitrogen should also be in 
quickly available forms, and should be supplied in suffi- 
cient quantities at time of setting the plant to enable it 
to mature, and thus to withstand the rigors of winter. 
Hence, an additional application of 100 pounds of dried 
blood, or its equivalent in nitrate of soda, is advisable, par- 
ticularly on soils not previously well enriched with organic 
nitrogenous matter. In the spring of the season during 
which the first crop is harvested, an application of a quick- 
acting fertilizer rich in nitrogen is desirable, since it not 
only provides for an early and strong growth of plant, but 
a better setting of fruit, if other conditions are favorable ; 
and frequently, with a full setting, top-dressings with 
nitrate of soda are useful, in order to insure the full develop- 
ment of the crop. Many growers, therefore, who have 
supplied the soil liberally with minerals and nitrogen, 
both at time of setting the plants and in the following 
spring, make top-dressings of nitrate of soda (about 100 
pounds to the acre), preferably after the plant has blos- 
somed, in order to insure a sufficiency of this element. 
This should be applied at this time rather than later 
in the season, since later applications have a tendency 
to cause a soft growth of fruit, and thus injure shipping 
qualities. 

Some growers find it a better practice to supply available 
nitrogen in the mixture used at the time of setting and in 



328 Fertilizers 

spring rather than make partial applications of nitrate of 
soda ; and others prefer to use nitrate of soda alone at the 
time of setting and supply the minerals as a top-dressing 
during the summer. If a complete fertilizer containing 
available nitrogen is to be used as above suggested, 400 to 
600 pounds of the formula given on page 313 would give 
excellent results. 

Raspberries and blackberries. 

Raspberries and blackberries also require a soil well 
enriched with the mineral elements, which insure an abun- 
dant and strong growth of canes. The need for nitrogen, 
while apparent, is less marked than in the case of the straw- 
berries, and the slower-acting forms serve a good purpose, 
provided they are not applied in too great quantities, so as 
to encourage a late growth of plant, which does not fully 
mature. The main object is to obtain strong, well-ripened 
canes, and this can be accomplished with the slowly avail- 
able nitrogenous substances, provided an abundance of the 
minerals is present. An annual application in spring of 
500 pounds to the acre of basic formula No. 2 (p. 313) will 
furnish sufficient food on soils of good character, though on 
lighter soils additional nitrogen should be supplied, pref- 
erably in forms not too active. The practice of applying 
quick-acting nitrogen early in the spring, after plants 
have blossomed, has been followed with great success, 
particularly upon the lighter soils, as it encourages a 
more complete development of fruit, though it should 
be used with caution, since the fruit canes of both the 
present year and those which provide the plant for the 
next year naturally grow in the same bed, and the young 
canes may not mature properly if too heavy applications 
of nitrogen are made. 



Orchard Fruits and Berries 329 

Currants and gooseberries. 

These are crops which, under average conditions, are 
seldom heavily fertilized, though fertilizing is usually 
followed with great profit. They are less likely to need 
nitrogen than the other crops mentioned, and a too heavy 
fertilization with this element has a tendency to encourage 
the development of mildew, the disease so common to these 
crops. In common with the other crops mentioned, they 
should be abundantly supplied with the minerals, phos- 
phoric acid and potash, and the basic formula already 
recommended (p. 313) may be used in all cases with profit 
at the rate of 500 to 1000 pounds to the acre. The addi- 
tional nitrogen needed may be provided by the slow-acting 
materials. Many growers find such waste products as 
wool and hair of great advantage in the growing of these 
crops. 

Cranberries. 

This crop is very peculiar in its habits of growth, and 
also in its choice of soils. It thrives upon muck soils and 
upon sand. Experiments conducted by the New Jersey 
Experiment Station show that the value of fertilization 
of cranberries depends quite as much upon the drain- 
age and irrigation of a bog as it does upon the soil. 
When these conditions are satisfactory, liberal applica- 
tions of minerals, particularly phosphoric acid, upon 
muck soils increase the growth of vine and the size and 
quantity of the berries. On such soils 400 pounds of acid 
phosphate and 100 pounds of muriate of potash may be 
applied. 

Upon light, sandy soils, nitrogen is quite as important as 
phosphoric acid and potash, but it is necessary to exercise 



330 Fertilizers 

great care in the application of nitrogen because it is likely 
to cause too great a growth of vine at the expense of 
fruiting. In general 150 pounds of nitrate of soda, 300 
pounds of acid phosphate and 100 pounds of muriate of 
potash to the acre is sufficient where a uniform growth 
of vine is present. At all events, the fertilization of cran- 
berries is of very recent origin and no definite rules can be 
laid down. It is an individual problem with each grower. 
The recommendations above are based upon work done 
by the New Jersey Experiment Station by the author. 
The results obtained by the Massachusetts Experiment 
Station under Cape Cod conditions seem to contradict the 
New Jersey results. 

GRAPES 

Grapes are more exhaustive as a crop than most of the 
fruit crops, largely because of the larger total crop har- 
vested, and the special need is for phosphoric acid and 
potash. These elements may be supplied by the basic 
formula (p. 313), and very liberal dressings are recom- 
mended — from 1000 to 2000 pounds to the acre annually 
— after the bearing period begins. On light soils, an 
annual spring dressing of nitrate of soda, at the rate of 
200 pounds to the acre, is also desirable, in order to encour- 
age rapid and large early growth of leaf and vine, though 
this dressing may be omitted if the growth of clover as a 
green-manure is practicable. The latter, however, as when 
used in connection with the other fruits mentioned, should 
not be allowed to mature, but rather be plowed down early 
in the season. 

The main point in the fertilizing of all fruits is to pro- 
vide an abundance of the mineral elements, and to give 



Orchard Fruits and Berries 331 

particular attention to fertilization with nitrogenous 
materials. It must be remembered that it is the fruit, 
not the wood, that constitutes the crop, and that all the 
energies should be directed toward the development of 
such a tree or vine as will best contribute toward this end. 



CHAPTER XVII 
FERTILIZERS FOR VARIOUS SPECIAL CROPS 

In addition to the generally familiar crops already- 
described, there are certain special ones, not distinct 
from the others because they are of less importance, 
but rather because they are only grown in certain lo- 
calities. 

COTTON 

Among these special crops, cotton takes first rank, 
because it is one of the leading crops of the country, 
occupying wide areas, and exercising fully as great an 
influence upon our agricultural prosperity as any other 
of our American staples. 

The climate suitable for the growing of cotton is con- 
fined to about one-quarter of the area of the country, 
and in this area it occupies a more important position 
than any other crop grown there. 

In the earlier history of its cultivation, the methods 
employed were not such as to encourage the largest 
yield. In the first place, it was grown on the poorer 
soils rather than on the more fertile, and after it had been 
grown consecutively upon the same lands for a number 
of years, and thus rapidly exhausting them, the planter, 
instead of attempting to improve the lands, either by 
better methods of culture or by the use of manures, 
extended the areas under cultivation. After the civil 

332 



Fertilizers for Various Special Crops 333 

war, when it became still more necessary to change 
methods, fertilizers were looked to as the main reliance, 
rather than the improvement of the character of the soil, 
either by judicious rotation or by manuring. The results 
secured from the use of fertilizers at this time were so 
generally satisfactory that their large and indiscriminate 
use was encouraged, and this, without proper attempts 
at the improvement of the soil in other respects, hastened 
the time when such use did not give profitable returns. 
The very great importance of the crop to the agriculture 
of the leading cotton states, and the necessity of better 
methods of culture, were so fully appreciated that a scien- 
tific study of the crop was then entered upon, and the 
states largely interested planned, through the aid of their 
colleges and experiment stations, a wide series of experi- 
ments, which were directed toward the solution of the 
problems connected with the feeding of the plant. The 
results of these experiments have been fruitful of such 
valuable information as to warrant practical and specific 
suggestions which have a wide application, and which, if 
followed, will result in the improvement of the soil and in 
the economical increase in crop. 

As already stated, the cotton crop is not an exhaustive 
one in one sense, though the methods of practice used in 
its growth have been wasteful, and thus have given rise 
to that belief. That is, a large crop of cotton does not 
remove from the soil a very considerable amount of the 
fertilizer constituents. The following amounts are con- 
tained in a crop yielding 300 pounds of lint to the acre : 1 

Nitrogen 46 lb. 

Phosphoric acid 12 lb. 

Potash 30 lb. 

1 Farmers' Bulletin, No. 14, Department of Agriculture. 



334 Fertilizers 

Fertilizers for cotton. 

In regard to its need for fertilizing, cotton may be 
classed with the cereals rather than with the crops already 
discussed ; and like the cereals, its best growth is at- 
tained when properly introduced into a rotation with 
other crops, and the annual food supply arranged in such 
a manner as to contribute to the larger yield of the imme- 
diate crop, as well as to furnish an unused residue which 
will provide for an increase in the yield of the succeeding 
ones. Of the constituents, phosphoric acid seems to 
exercise a greater influence upon the growth and develop- 
ment of the cotton plant than any other element, not- 
withstanding the fact that smaller amounts are contained 
in it than of either nitrogen or potash. That is, it appears 
that the plant must have an abundance of available phos- 
phoric acid at its command in order that the other con- 
stituents necessary for a full crop may be freely absorbed, 
though on the soils adapted for the crop, which naturally 
vary widely both in their general and special physical 
characteristics, but are poor in the fertility elements, 
both nitrogen and potash must be applied, in order that 
maximum crops may be obtained. 

On the whole, therefore, though the "intensive" 
system is not generally practiced, fertilizers furnishing 
all of the constituents are superior to those which fur- 
nish but one or two ; yet when proper rotations are prac- 
ticed and leguminous crops are grown for the purpose of 
improving the physical character of the soil, as well as 
increasing its content of nitrogen, the percentage of this 
element introduced into the fertilizer may be very largely 
reduced. 

The conclusions that have been arrived at by the 



Fertilizers for Various Special Crops 335 

experiments conducted in the various states have been 
very fully set forth in various publications, 1 and the 
following statements drawn from these indicate what 
are believed to be the advantages derived from the right 
use of fertilizers, and the best methods to be observed : 
"The cotton plant responds promptly, liberally and 
profitably to judicious fertilization. The maturation 
of the crop may be hastened, and the period of growth 
from germination to fruiting may be so shortened as to 
increase the climatic area in which it may be profitably 
grown. It should be assigned to a place in a rotation 
system. One of small grain, corn (with peas) and cotton, 
is well suited for the conditions prevailing in the cotton 
belt, and, as with other crops, the results derived from 
the use of fertilizers for this crop are much enhanced by 
the proper preparation of the soil. It pays to bring 
up the cotton lands by mechanical treatment, and es- 
pecially by introducing organic matter. The renovating 
crops, especially the cowpea, are very profitably employed 
as adjuncts to the fertilization of the crop itself. On the 
majority of soils, too, it is advisable, and more generally 
proves profitable, to use a complete fertilizer, rather than 
one containing one or two of the constituents ; and of the 
forms of nitrogen, organic (vegetable and animal) is best 
suited to the cotton, if one form alone be used, although 
nitrate of soda is probably nearly, if not quite, of equal 
value. The relative advantages of various proportions 
of the different forms have, however, not yet been fully 
determined; hence the use of a mixture of the best is a 

1 Farmers' Bulletins, Nos. 14 and 48, Department of Agri- 
culture. Office of Experiment Stations, Bulletin No. 33, De- 
partment of Agriculture. Various bulletins issued by the 
Georgia, South Carolina and Louisiana Experiment Stations. 



336 Fertilizers 

safe plan, the proportions to be determined by their rela- 
tive cost. In the case of phosphoric acid, superphosphate 
is to be preferred to materials of an organic or mineral 
nature, which are not immediately available. Of the 
potash salts, no particular difference is observed in the use 
of the different forms. The form to be secured is to be 
based upon the price of the different forms." 

Formulas for cotton fertilizers. 

While the most judicious proportions of soluble phos- 
phoric acid, of potash and of nitrogen in a complete 
fertilizer cannot be said to have been determined with 
entire accuracy, the carefully conducted experiments of 
both the Georgia and South Carolina stations indicate 
that for general use 1 part of nitrogen, 1 of potash and 
2f or 3 of phosphoric acid indicate the best proportions. 
The amount of fertilizer that may be profitably used very 
naturally varies widely, though medium rather than 
very large dressings are recommended, not so much be- 
cause the plant under good soil conditions could not appro- 
priate and use to advantage large amounts, but because 
on the whole, soils used for cotton are peculiarly lacking 
in those qualities which enable the proper distribution 
and appropriation of the larger quantity. For those soils, 
then, the amounts per acre indicated by the Georgia 
Experiment Station are annually — 

Nitrogen 20 lb. 

Available phosphoric acid 70 lb. 

Potash 20 lb. 

The South Carolina Experiment Station recommends 
an acre application of — 



Fertilizers for Various Special Crops 337 

Nitrogen 20 lb. 

Available phosphoric acid 50 lb. 

Potash 15 lb. 

or, as suggested by the Georgia Experiment Station, 
perhaps a fertilizer containing — 

Nitrogen 3% 

Phosphoric acid (soluble) 9% 

Potash 3% 

applied at the rate of 700 pounds to the acre, would be 
approximately the best amounts to use under ordinary 
circumstances. 

Method of application. 

The fertilizer should be applied in the drill at the 
time of planting, and at the depth of not more than 
three inches, and well mixed with the soil. In most cases 
it is best to apply all of the fertilizer in one application 
rather than in fractional applications, though with lands 
in superior condition profitable applications may be made 
again at the second plowing. Owing to the nearness of 
the cotton belt to the supplies of superphosphate, and to 
the cheap supplies of cotton-seed meal, the only fertilizer 
necessary to import is potash. Hence it has become a 
practice in most sections for the planter to make his own 
formulas, using his own supplies of phosphoric acid and 
nitrogen ; and home mixtures, made up of acid phosphate, 
cotton-seed meal and muriate of potash, or kainit, are 
largely used to supply the demands. The following for- 
mula is an example of a good mixture : 

Acid phosphate 1200 lb. 

Cotton-seed meal 600 lb. 

Kainit 200 lb. 



338 Fertilizers 

The formula containing — 

Nitrogen 3% 

Phosphoric acid 9% 

Potash 3% 

is also recommended, since an application of 700 pounds 
per acre will furnish the amounts and proportions of the 
elements indicated as the maximum by the Georgia sta- 
tion. This formula is also well suited for corn, if intro- 
duced into a rotation as previously suggested. 

tobacco. (See Fig. 32, Plate XVI.) 

Tobacco is another special crop grown only in cer- 
tain localities, favored either by reason of climate or 
character of soil, or both. It is, however, a very im- 
portant crop in this country, and one which requires 
very careful attention in reference to the amounts and 
kinds of fertilizers applied, because the fertilization exer- 
cises an influence upon both the yield and quality of the 
crop. It is an exhaustive crop, drawing heavily upon 
both nitrogen and potash. A crop yielding 1000 pounds 
of leaf to the acre will contain, in round numbers, 67 
pounds of nitrogen, 9 of phosphoric acid and 85 of potash : 
amounts equivalent in nitrogen to over 400 pounds of 
nitrate of soda, of phosphoric acid equivalent to 75 pounds 
of acid phosphate, and of potash equivalent to 170 pounds 
of muriate of potash. It is a fact, too, that tobacco of the 
best quality, or that best suited for cigar wrappers, can 
be grown to advantage only on light, sandy soils, — those 
not naturally well supplied with the fertilizing constit- 
uents. Thus, if large crops are to be secured, the soil 
must receive liberal supplies of food from artificial sources. 





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Fertilizers for Various Special Crops 339 



The influence of fertilizers on the quality of the crop. 

A point of great importance in the fertilizing of tobacco 
is the influence of the constituents applied on the market- 
able quality of the crop, as for certain purposes, espe- 
cially for the manufacture of cigars and cigarettes, the 
tobacco must possess peculiar characteristics in order 
to bring the highest price in the market. In other words, 
in the growing of this crop, as is the case in many others, 
both the yield and quality must be taken into considera- 
tion, and frequently the latter point is of quite as much 
importance as the former, though a reasonable yield must 
be secured before the influence of quality is of practical 
significance. The quality of the leaf is believed to be 
influenced chiefly by the constituent potash, though 
many growers object to the use of various nitrogenous 
and phosphatic materials, believing that they, too, exer- 
cise a decidedly unfavorable influence upon the quality 
of the leaf. Careful experiments, however, do not justify 
many of the opinions of growers and dealers regarding the 
effect of the different materials upon the quality of wrapper 
tobacco. 

The main points, therefore, in the fertilizing of tobacco 
are to see to it that a sufficient quantity of plant-food is 
applied in order to secure the largest possible yield con- 
sistent with quality, and second, to avoid the use of such 
constituents as are positively injurious. 

The conclusions from Connecticut experiments. 

Experiments in the application of fertilizers to to- 
bacco have been carried out at the Connecticut Experi- 
ment Station with great care and skill for a number 



340 Fertilizers 

of consecutive years. 1 They lead to the conclusion 
that "there is no 'best' tobacco fertilizer, or 'best' 
formula for all seasons, even on the same soil. A for- 
mula or a form of plant-food which in one season gives 
the leaf a somewhat better quality than any other may, 
perhaps the next year and on the same soil, prove inferior 
to others, for reasons which can only be surmised. 

"Nevertheless, by comparing the effects of these 
fertilizers for a term of years, it appears that certain 
ones are, on the whole and generally speaking, more 
likely to impart a perfectly satisfactory quality to the 
leaf than certain others. 

"It is doubtless true of tobacco, as of other crops, 
that the liberal but not greatly excessive supply of readily 
available plant-food yearly required to insure a paying 
crop may be given in a variety of forms with equally 
good results, on the average of one season with another, 
and that, indeed, occasional changes in the form of nitro- 
gen and potash supplied may be a distinct advantage, 
avoiding always any considerable quantity of those 
things, as chlorin, and sulfuric or other free acids, which 
experience has shown may damage the leaf." 

These conclusions in regard to the kind and quantity 
of fertilizing constituents required for the growing of 
tobacco of good quality confirm those arrived at by 
experiments elsewhere, and the suggestions made are 
sufficiently definite to guide in the use of fertilizers 
for this crop. In brief, therefore, the tobacco crop 
must be provided with an abundance of all of the fer- 
tilizer elements derived from readily available forms, 
and free from those constituents known to exercise an 

1 Connecticut Agr. Exp. Sta. Annual Report, 1897, Part IV, 
page 255. 



Fertilizers for Various Special Crops 341 

unfavorable influence upon the quality of the product, 
in order that satisfactory yields of good quality may be 
secured. 

Form of the constituents. 

It has not been shown that one form of nitrogen is 
superior to another under all circumstances, or in other 
words, that one form of nitrogen — as, for example, 
ammonia, or nitrate, or any particular form of organic 
nitrogen, vegetable or animal — is superior to all others, 
but rather that any or all of the good forms may be used 
in a mixture, provided a sufficient abundance is present 
to insure a maximum yield, though not so large an amount 
in excess of the minerals as to encourage a rank, coarse 
growth. Phosphates have been neglected because the 
crop takes out very little, but recent tests indicate that 
moderate use of them gives a healthier crop, a somewhat 
larger crop and perhaps of somewhat better quality. 
The phosphoric acid should be in available forms, and if 
in these forms, must naturally be drawn largely from 
superphosphates. The potash should in all cases be drawn 
from sources free from chlorids. A fertilizer, therefore, 
which contains the nitrogen, either in good organic forms, 
as cotton-seed meal or blood, or a mixture of these organic 
forms with ammonia or nitrate in not too large amounts, 
which contains the phosphoric acid in a soluble form, and 
potash derived from products free from chlorids, — as 
from high-grade sulfate, or from a carbonate, or from 
cotton-hull ashes, if these are obtainable, — may be re- 
garded as well adapted for the crop. 

Amounts to apply. 

An annual dressing which will furnish 100 pounds of 
nitrogen, 75 of phosphoric acid and 150 of potash to the 



342 Fertilizers 

acre may be regarded as a minimum for soils of medium 
quality. On lighter soils heavier applications should 
be made, and on soils previously well enriched with the 
fertilizer constituents, the dressing may be somewhat 
less. It must be remembered, however, that it is not 
economical, from the standpoint of either yield or qual- 
ity, to be too sparing in the application of fertilizers, 
because the plant requires large amounts of both nitro- 
gen and potash, and because it is essential that the plant 
should have a reasonable excess of these at its command, 
in order to overcome as far as possible any unfavorable 
seasonal conditions that may occur. 

In the Connecticut experiments already referred to, 
amounts greatly in excess of those suggested have been 
used with advantage, and the following formulas are cited 
as fair examples of what would be good fertilizers for an 
acre: 

Cotton-seed meal 2000 lb. 

Sulfate of potash 300 lb. 

Precipitated or dissolved bone . . . 200 lb. 

Lime 300 1b. 

Total . . 28001b. 
or 

Cotton-seed meal 1500 lb. 

Fish 500 1b. 

Double sulfate of potash 500 lb. 

Acid phosphate 400 lb. 

Lime 300 1b . 

Total . . 3200 lb. 

In Kentucky and Virginia, on soils naturally richer, 
smaller amounts have given quite as good results. It is 
likely, however, that upon the very light soils of certain 
of the states in which tobacco of high quality is grown, 
notably Florida, considerably increased amounts may be 
used with profit. 



Fertilizers for Various Special Crops 343 

As sources of at least part of the nitrogen and potash 
in the southern states particularly, cotton-seed meal and 
cotton-hull ashes are recommended, because readily 
obtainable. These forms have been found to be good, 
and they may be obtained as cheaply as other forms as 
well as more conveniently. 

SUGAR-BEETS 

The purpose in the growth of sugar-beets is to obtain 
the largest total yield of sugar to the acre ; and inasmuch 
as the sugar content of the beet, as well as its right growth 
and development, is very largely influenced by the char- 
acter of the fertilization, this matter becomes of very 
considerable importance, in view of the promising devel- 
opment of the sugar-beet industry in this country. Thus 
far, information concerning the use of fertilizers is derived 
largely from the results obtained in other countries, 
where it has been a prominent crop, and where great 
attention has been paid to this factor in its production. 

The demands of the crop for plant-food. 

The sugar-beet draws heavily upon the soil for the 
nitrogen and potash constituents. A minimum yield of 
10 tons of topped beets contains 44 pounds of nitrogen, 
20 of phosphoric acid and 96 of potash. On medium, 
loamy soils, which by their character are well adapted 
for the growth of the sugar-beet, heavy fertilization 
with potash, however, has not been found to be desirable ; 
while on light soils, which are also well adapted for the 
crop, liberal manuring with potash becomes absolutely 
necessary. 

As in this crop, the object of the growth is to secure 



344 Fertilizers 

not primarily beets, but sugar, and since the sugar for- 
mation is not perfected until the absorption of the neces- 
sary food from the soil has been in large part completed, 
any fertilization which promotes a too rapid or too long- 
continued growth has a tendency to reduce the percentage 
of sugar; and inasmuch as the maturation takes place 
largely in the months of early fall, the growth must be 
forced early in the season. That is, it is essential that a 
large and rapid leaf growth be made early, in order that 
the food from the air may be acquired. It has been demon- 
strated that for this early and rapid growth of the beet, 
phosphoric acid is one of the most essential constituents, 
which explains the need for phosphoric acid in larger pro- 
portion than is indicated by the composition of the beet. 
The crop requires a considerably greater supply of phos- 
phoric acid at this stage of its growth than other farm 
crops which are quite as exhaustive, and it is also evident 
that in order that the crop may obtain the phosphoric 
acid at this period, it must be soluble and immediately 
available; hence the larger portion of this element 
applied should be derived from superphosphates. In 
the matter of fertilization with nitrogen, the object of 
the growth must also be kept in view. An application 
which would encourage steady and continuous growth, 
rather than an early and rapid growth, while contributing 
to a large yield, causes a reduction in the sugar content 
of the beet. Hence it is strongly urged by those who are 
in a position to give sound advice, that the early nitrogen 
fertilization should consist of the quickly available forms, 
nitrate or ammonia, and that the organic or slower-acting 
forms should not be applied in such excess as to encourage 
a late growth. Hence it is, that upon medium and light 
lands the use of commercial fertilizers has proved of greater 



Fertilizers for Various Special Crops 345 

service in the growing of this crop than the exclusive use 
of yard manure, and in such quantities as to supply the 
entire needs of the plant. In the use of fertilizer, not 
only the total supply of the constituents, but their form, 
may be regulated to the needs under different conditions, 
thus permitting a full feeding of the plant, and at a time 
most suitable to accomplish the object in view, — advan- 
tages which are not possessed by the natural manures. 

A fertilization which would meet the needs both in 
respect to quantity and kind of fertilizers may be as 
follows : 

On good soils, the application of a fertilizer contain- 
ing from 40 to 50 pounds of nitrogen, from 50 to 60 of 
phosphoric acid and from 40 to 50 of potash would be 
sufficient to meet the demands of the plant. The nitro- 
gen supplied should be derived largely from nitrates or 
ammonia, or both, and the phosphoric acid from a super- 
phosphate, while the potash may be derived from sulfate 
or muriate of potash. The former is preferable if applied 
during the spring preceding the planting of the beets. 
While it is frequently desirable, for convenience and 
economy of labor in applying, that the fertilizer should 
be mixed, in order to prevent any waste of soluble nitro- 
gen, it should be applied in fractional dressings. For 
example, a mixture of 250 to 300 pounds of nitrate of 
soda (or the nitrogen may be derived partly from nitrate 
and partly from ammonia), 400 to 500 pounds superphos- 
phate and 80 to 100 of muriate or high-grade sulfate of 
potash should be applied in two or three dressings. A 
part only should be applied previous to sowing, for both 
the nitrate and the potash salts have a depressing effect 
upon germination. They are preferably applied, say, 
one-third of the mixture as soon as the plants have come 



346 Fertilizers 

up, another third immediately after or before the first 
cultivation, and the remainder immediately after or before 
the second cultivation. The application of the fertilizers 
in these forms and at the times indicated insures the rapid 
and early growth and development of the plant ; and by 
reason of the solubility of the nitrates and ammonia salts, 
a late feeding of the plant with nitrogen is obviated. 

On light or medium soils, the amount of plant-food 
should be increased by at least one-third, though frac- 
tional applications should be made as previously recom- 
mended. On soils rich in vegetable matter, a part of the 
nitrogen may be omitted, though the phosphoric acid 
should not be reduced. 

The influence of previous deep cultivation of soil. 

Another point to observe in the growing of beets for 
sugar — and it also has an immediate bearing upon 
fertilization — is the character of the previous cultiva- 
tion. If the soils have not been deeply and well culti- 
vated, so large a dressing as is here recommended would 
be likely to be deleterious, as with a shallow and poorly 
prepared soil plants would have less opportunity to pene- 
trate deeply, and thus too great a growth above the sur- 
face of the ground would be encouraged, with a consequent 
lowering of sugar content as well as yield. 

The best practice in this country will have to be devel- 
oped by the experience of our own growers, although in 
the absence of such experience the recommendations 
here made may be relied upon. In many sections in 
which soils and climate are well adapted for the sugar- 
beet, the needs as yet are quite as much for improved 
methods of cultivation as for added fertility. They have 
not been exhausted of their essential fertility. 



Fertilizers for Various Special Crops 347 

SUGAR-CANE 

Another special crop, confined largely to one state, 
Louisiana, is sugar-cane, and perhaps no other one crop 
has in this country received such careful study in refer- 
ence to its needs for plant-food. The Sugar Experiment 
Station of that state has for twelve years conducted a 
series of systematic experiments designed to answer the 
questions as to what the needs are for nitrogen, phos- 
phoric acid and potash ; and the results of this work thus 
far secured furnish suggestions in reference to fertiliza- 
tion, which will, if carefully followed, undoubtedly result 
in the production of better crops than are grown under 
present systems. Fertilizers are clearly needed, and their 
right use is a profitable practice, though, as stated by 
Doctor Stubbs, "many ascribe the failure from their use 
to the worthlessness of the fertilizer, when it should be 
ascribed to some defection of the soil, rendering it incapable 
of appropriating the applied fertilizer." 

The chief conclusions in reference to fertilizers for 
sugar-cane in Louisiana, so clearly set forth by Doctor 
Stubbs in this report, 1 are here summarized, as it is be- 
lieved that the underlying principles are applicable else- 
where, though naturally their use must be modified to 
suit individual cases. 

The needs of the plant as indicated by the Louisiana experi- 
ments. 
"An examination of the cane plant shows that a crop 
of 30 tons will remove, in round numbers, 102 pounds of 
nitrogen, 45 of phosphoric acid and 65 of potash. It is, 
therefore, a relatively exhaustive crop, and unless the 

1 " Sugar-cane," Vol. I, Sugar Experiment Station, Audubon 
Park, New Orleans, La. 



348 Fertilizers 

physical conditions are perfect, even good soils should 
receive considerable dressings of the constituents, if the 
fertility is to be maintained. 

"The results secured thus far in the experiments 
referred to demonstrate that the soil needs nitrogen 
and phosphoric acid particularly, in order to grow cane 
successfully, while thus far, no results of any character, 
either in the increased sugar content or tonnage per acre, 
have been visible from the use of any form of potash upon 
the alluvial lands of the lower Mississippi. Several forms 
of potash, notably the carbonate, and ashes of cotton-seed 
hulls, have rather decreased the yield of cane and injured 
the physical qualities of the soil by causing it to 'run 
together.' 

"In reference to the form and amount of nitrogen, 
it has been shown that sulfate of ammonia gives slightly 
better results than any other form, though its higher cost 
gives no advantage over those costing less, while cotton- 
seed meal comes next, followed by dried blood and nitrate 
of soda. In reference to the amount of nitrogen to be 
applied, it is shown that not less than 24 pounds nor more 
than 48 pounds to the acre should be applied. Naturally, 
different soils and different kinds of cane would vary in 
their requirements for this element, and the amount 
needed would also be influenced by the method of growing 
the crop : whether upon ' succession' land — that is, upon 
soils upon which a crop of stubble cane has just been 
taken off, and which has been in cane for a number of 
years without the intervention of a leguminous crop be- 
tween to restore the nitrogen — or whether upon pea- 
vine land, upon which the plant cane is grown the first 
year, stubble cane the second, and corn and cowpeas the 
third year. This system of rotation, which introduces a 



Fertilizers for Various Special Crops 349 

leguminous crop into it, not only improves the physical 
quality of the soil, but enables a considerable accumula- 
tion of nitrogen, frequently over one hundred pounds per 
acre. The pea-vine lands, put in plant cane on account 
of their excellent physical condition, not only yield up 
readily the nitrogen stored up by the pea, but can also 
assimilate larger quantities of plant-food applied as 
fertilizer. Hence, such cane usually makes large crops. 
Since nitrogen is the chief ingredient taken from the soil 
by a crop of cane, it follows that with each successive 
crop of cane grown on the land without the interjection 
of the leguminous nitrogen there arises an increased de- 
mand for nitrogen. Hence, stubble cane requires larger 
quantities than plant cane, and the older the stubble, 
the larger its requirements for this element." 

In reference to phosphoric acid, the results so far 
indicate positively the value of this element in fertilizers 
for sugar-cane on these soils, but the demand for this 
ingredient is small in comparison to that for nitrogen, 
36 pounds to the acre being ample for the crop. The 
results further show that the soluble forms of phosphoric 
acid are preferred. Inasmuch as the leguminous crop 
does not add to the store of phosphoric acid in the soil, 
it is equally needed by both plant and stubble cane. 

While potash has not been shown to be needed on 
the land upon which the experiments were conducted, 
because of the abundance of potash contained in the 
soil, after continuous cropping of these and on lighter 
soils this element should be included in the fertilizer. 

The application of fertilizers. 

For plant cane, a small quantity of readily available 
fertilizer directly under and near the cane is highly 



350 Fertilizers 

beneficial, as it provides food also for the sucker, which, 
with food at hand, is greatly aided in developing a healthy 
sucker, and thus the entire plant is given a vigorous send- 
off in youth. It is necessary, to give a good start to a 
young plant, to withhold manures until a stand is secured, 
though when cane is planted during the fall and winter, 
as it is in Louisiana, the danger of loss by leaching must 
be reckoned upon, and the exact amounts to be applied 
at that time regulated by the judgment of the planter. 
Usually the more perfect the incorporation of a manure 
in the soil, the better the results to be expected, but in this 
case it should be deposited in a drill and well mixed with 
the soil. In the spring, after the cane is closely off-barred, 
the fertilizer, if not applied at planting, should be scat- 
tered on both sides of the plant from the center of the row 
to the off-barred furrow. Thus, in reversing the furrow, 
the manure is covered, and subsequent cultivation will 
mix the latter with the soil. If the cane has received the 
first application at planting, the second one should be 
given in May, on both sides of the row. The stubble 
cane should not be fertilized very long before each sprout 
has sent out its own rootlets, since prior to this no good 
could be accomplished, and there would be a waste of 
manure. 

HOPS 

Little interest has been taken in the matter of ferti- 
lizers for hops because they are grown largely upon very 
rich soils in the West where little fertilizer is used, while 
in the East the interest in hop-culture is decreasing. 
Farm manure is at present the standard fertilizer, but 
many growers are now beginning to use commercial fer- 
tilizers. In the fertilizing of hops, the quality of the 



Fertilizers for Various Special Crops 351 

product is an important consideration, and an excess of 
available nitrogen which is liable to cause a too rank 
growth and green hops of an undesirable quality should 
be avoided . Hence, 600 to 800 pounds of th e following mix- 
ture would supply sufficient plant-food in the right forms : 

Nitrate of soda 50 lb. 

Dried blood 100 lb. 

Tankage 200 lb. 

Acid phosphate 450 lb. 

Muriate of potash 200 lb. 

FLAX 

Flax is a peculiar crop to feed because it has a very 
fine tap root and few root-hairs, and because it makes its 
growth in a relatively short period of time, forty or fifty 
days, it is often termed a dainty feeder. Few investi- 
gations have been made to determine the best kinds and 
amounts of plant-food to use. The practice of successful 
growers seems to show that liberal applications of manure 
or the use of green-manure for two or more seasons sup- 
plemented with nitrate of soda as needed gives satisfactory 
results. In the absence of farm manure or green-manure, 
300 to 400 pounds of a mixture made as follows should 
supply sufficient amounts of the elements, though nitrate 
of soda may still be used, as needed, as a top-dressing : 

Nitrate of soda 250 lb. 

Dried blood 100 lb. 

Acid phosphate 500 lb. 

Muriate of potash 150 lb. 

MISCELLANEOUS CROPS 

Other crops of importance for which the need of fer- 
tilizers is frequently apparent include sorghum, buck- 



352 Fertilizers 

wheat, peanuts, roses and herbaceous plants, lawns, 
grasses and plant-house vegetables. These are, of course, 
similar to those already described, since their best devel- 
opment requires that they shall be well supplied with the 
fertilizing constituents, nitrogen, phosphoric acid and 
potash, though their special needs in this respect have not 
been so fully investigated as the other crops dealt with 
in this chapter. The discussion of their requirements is, 
therefore, necessarily brief, and the suggestions made 
are of a general rather than a special character, though 
they may serve as a safe guide. 

* 

Sorghum. 

Sorghum is grown both for forage and for sugar, and 
its fertilization should be discussed from these two stand- 
points. If grown for forage, the fertilization should be 
more liberal and of a different character than if for sugar, 
as the object is the largest yield of succulent food rather 
than the highest yield of sugar, and the yield of sugar is 
not always consistent with the highest yield of cane. 
For forage, therefore, the fertilizer recommended for 
maize forage (p. 262) is well adapted for sorghum on soils 
in a good state of fertility, though since the plant is very 
slow to start, its early growth is stimulated if a larger 
amount of readily available nitrogen is used than is de- 
sirable for corn, particularly on soils of medium fertility, 
and which have not been previously well fertilized. If 
grown for sugar, too much nitrogen must be avoided, 
since an excess of this element in the fertilizer causes an 
imperfect ripening, and consequently a higher percent- 
age of non-crystallizable sugar in the cane; though if 
quickly available forms are used, as nitrate, ammonia 
or dried blood, which may be absorbed by the plant 



Fertilizers for Various Special Crops 353 

early in the season, a larger amount may be applied with 
safety than if the poorer forms are used. Of the three 
constituents, potash in the form of muriate seems to be 
the one exercising the greatest influence upon the yield of 
sugar, hence it should always be introduced in consid- 
erable amounts in fertilizers for sorghum. 1 A fertilizer 
furnishing 20 pounds of nitrogen, 35 of phosphoric acid 
and 60 of potash to the acre will meet the needs on aver- 
age soils. 

Buckwheat. 

Buckwheat is frequently grown upon the poorer soils 
of the farm. It is a crop well adapted to mountain lands, 
and as a preparatory crop in the breaking of new lands. 
It has not been carefully studied in reference to its needs 
for plant-food, though phosphoric acid seems to be the 
constituent more particularly required than the others. 
Its need of nitrogen is marked, yet because its entire growth 
and development are made during the months of July and 
August, when conditions are most favorable for soil 
activities, heavy nitrogenous fertilization is not to be 
recommended, except when grown on very light soils, or 
those deficient in vegetable matter. The moderate use 
of fertilizers rich in minerals, and which contain nitrogen 
in quickly available forms, result favorably, not only in 
increasing the yield, but assist materially in maturing 
the crop, a matter of great importance. A fertilization 
with 25 pounds to the acre each of phosphoric acid and 
potash and 10 of nitrogen may be regarded as a good one 
for soils of medium character. 

1 Report for 1886, New Jersey Agricultural Experiment 
Station. 

2a 



354 Fertilizers 

Peanut. 

The peanut is a leguminous plant, and, like others of 
this family, is not specifically benefited by nitrogen, 
but responds readily to liberal dressings of phosphoric 
acid and potash. The fertilization suggested for green- 
manure crops, namely, a mixture of three parts acid 
phosphate and one part muriate of potash, or equal 
parts of acid phosphate and kainit, may be used for 
this crop with great advantage. The applications, if 
frequently made, need not exceed 300 to 400 pounds 
to the acre. Like other leguminous crops, it is specifically 
benefited by lime, medium dressings of which (20 bushels 
to the acre) should be made at least once in four years. 
In the districts in which this crop is successfully grown, 
lime marls are frequently obtainable at slight expense, 
and may be used with great advantage. 

Roses and other flowering plants. 

In the growing of roses and other herbaceous plants, 
of which the flowers constitute the crop, great care is 
usually taken in the preparation of the soil, and natural 
soils are seldom used. Notwithstanding the richness of 
the prepared soils, the crops are benefited by the addition 
of commercial fertilizers, particularly those phosphatic 
in their nature. Ground bone is especially useful, since 
it furnishes both nitrogen and phosphoric acid in slowly 
available forms, and usually sufficient nitrogen to meet the 
needs of the plant, as excessive quantities of this element 
cause a too vigorous and rank growth of foliage, which is 
not accompanied by profuse flowering. A good mixture 
for the prepared soils, therefore, may consist of four parts 
of ground bone and one part of muriate of potash, which 



Fertilizers for Various Special Crops 355 

may be applied at the rate of four pounds to the square 
rod of area, and well worked into the soil previous to set- 
ting the plants. The after fertilization may contain a 
larger portion of the soluble phosphoric acid, which is 
more readily distributed. The need for nitrogen is indi- 
cated by a yellow, rather than a bright green, color in the 
foliage. Nitrogen may be supplied by light dressings 
(2 to 1 pound to the square rod) of the active forms of 
this element, preferably nitrate of soda, because of its 
ready distribution. In the preparation of soils for these 
plants in the house, the mixture may be applied at the 
rate of 2 pounds for every 100 square feet of surface, the 
after application to consist of the more soluble forms as 
recommended for the hardy plants. An even mixture of 
nitrate of soda and acid phosphate may be used at the 
rate of one pound for every 100 square feet of surface 
once in two weeks, if the plants do not show vigorous 
growth. 

Lawn grasses. 

The fertilization of lawns is also important in a sense, 
because proper fertilizing obviates the necessity of the 
home manures, which, although excellent as sources of 
the constituents, are frequently offensive. The use of 
manure also involves considerable labor, both in the ap- 
plication and the consequent removal of the coarse part 
in the spring, besides resulting in the introduction of 
weed seeds. In the preparation of the soil for a lawn, 
it must be supplied with an abundance of all of the neces- 
sary fertilizer ingredients previous to seeding, and of these 
phosphoric acid and nitrogen are especially important. 
Too great an excess of potash encourages the development 
of the clovers rather than the grasses. This preparatory 



356 Fertilizers 

fertilizer may contain the more slowly available forms 
of nitrogen and phosphoric acid. Ground bone is an 
excellent source of these elements, and a mixture of five 
parts of ground bone and one of muriate of potash makes 
an excellent dressing. This may be applied at the rate 
of five pounds to the square rod, and thoroughly worked 
into the soil. The after-fertilization may consist chiefly 
of nitrogen, preferably as a nitrate, since its ready solu- 
bility permits of its free penetration into the lower layers, 
which encourages a deeper root system, and thus greater 
resistance to drought. 

The top-dressings with nitrate of soda should con- 
sist of light fractional dressings, rather than of large 
amounts at one time. One-half pound to the square 
rod, twice or thrice during the season, — the first as soon 
as the grass is well started in the spring, and preferably 
immediately preceding a rain, — will, if the land has been 
previously prepared well, be sufficient. To facilitate 
the distribution of the nitrate, as well as to supply a suffi- 
cient abundance of phosphoric acid, it may be mixed with 
equal parts of ground bone. 

Forcing-house crops. 

A rich garden loam, to which a considerable pro- 
portion of stable manure — one-third to one-half the 
bulk — has been added, is the usual type of soils for 
such crops as tomatoes, lettuce, radishes and cucumbers 
under glass. The addition of fertilizers to these is seldom 
advisable. It has been demonstrated, however, that such 
mixtures are not essential, and that the crops may be 
profitably and successfully grown in mediums which 
contain no plant-food, 1 if supplied with an abundance in 

1 Connecticut State Experiment Station Reports for 1895, 
1896 and 1897. 



Fertilizers for Various Special Crops 357 

available forms from artificial sources. In the absence 
of good manure, which is the chief expense, a reasonably 
fertile loamy soil may be used for filling the beds, in which 
at the time of filling may be mixed, for each 100 square 
feet of surface, one-half pound of nitrate of soda, one 
pound of acid phosphate, one pound of ground bone and 
one-half pound of muriate of potash. This application 
will be sufficient to supply the needs of the plants for food 
until growth is well started, after which they should be 
fertilized at least once each week with one-quarter of a 
pound of nitrate of soda for every 100 square feet of 
surface area, and with the mineral fertilizers at the rate 
of one pound of acid phosphate and one-half pound of 
muriate of potash every two weeks. These may be ap- 
plied in solution, or evenly distributed over the surface 
of the soil, and worked in before watering. The amounts 
to apply should always be governed by the judgment of 
the grower. There is less danger from the application 
of too much, if properly used, than is commonly supposed. 



INDEX 



Agricultural salt, 115. 

Agricultural value of fertilizer, 178. 

Air-slaked lime, 139. 

Alfalfa, 273. 

Ammonia, 47 ; sulfate, 48 ; cal- 
cium cyanamid, 49 ; ammonium 
nitrate, 53. 

Ammonite, 39. 

Ammonium nitrate, 53. 

Analysis, see chemical analysis of 
fertilizers, 175-188 ; of plants, 
208. 

Animal bone, 62 ; raw, 63. 

Animal charcoal, 67. 

Animal matter, 39. 

Apatite, 71. 

Apples, 314. 

Application of fertilizers, 204; of 
lime, 148 ; of manures, 124. 

Apricots, 325. 

Artificial fertilizers: history of their 
use, 27 ; need of, 28 ; made neces- 
sary by increase in cost of labor, 
28; by demands for special 
crops, 30 ; by inadequacy of 
farm manures, 31 ; by demands 
of increased fruit production, 32 ; 
do artificial f ertilizers pay ? 33 ; 
unprofitable? 34. 

Ashes: coal, 112; corn cob, 113; 
cotton hull, 113; tan bark, 111; 
wood, 111. 

Asparagus, 314. 

Availability : different forms of 
nitrogen, 53 ; tables, 56 ; con- 
ditions which modify availability, 
57. 

Azotin, 39. 

Barley, 223 ; and peas, 266. 
Basic fertilizer: for market garden, 
287 ; for fruits, 313. 



Basic slag, 72 ; artificial basic slag 
meal, 73. 

Bat guano, 46. 

Beans, 258, 296. 

Beets, fertilizer constituents in, 16 ; 
for fodder, 280; for market 
garden crop, 289 ; beet tops, 294. 

Bermuda grass, 269. 

Berries (see Orchard fruits, 308) , 326. 

Blackberries, 328. 

Blood, dried, 37; red, 38; avail- 
ability, 56. 

Bone ash, 68; commercial grades, 
65; boiled, 64; fine, 63; phos- 
phate, 62 ; raw, 63 ; steamed, 64 ; 
tankage, 66. 

Bone meal : availability of nitro- 
gen in, 56. 

Broccoli, 293. 

Brussels sprouts, 293. 

Buckwheat, 353. 

Bulb crops, market garden, 29. 

Cabbage : green forage, 277 ; mar- 
ket garden, 293. 

Calcium, see Lime and calcium 
compounds, 135. 

Calcium carbide waste, 117; cyan- 
amid, 49; magnesium lime, 138; 
nitrate, 52; sulfate, 116, 144. 

Calculation of commercial value of 
fertilizers, 187. 

Carbonate of potassium, 99 ; double, 
98. 

Carnallit, 96. 

Carrots : fertilizer constituents in, 
16 ; forage crop, 280 ; market 
garden, 289. 

Castor pomace, 44. 

Cauliflower, 293. 

Celery, 295 ; fertilizer constituents 
in, 16. 



359 



360 



Index 



Cereals, 200, 212 ; experiments to 
determine lacking elements in 
soil, 214 ; importance of system, 
219 ; crops in rotation, 220 ; 
Indian corn, 220 ; oats, 222 ; 
barley, 223; wheat, 224 (con- 
tinuous wheat, 232) ; rye, 225 ; 
clover, 225 ; timothy, 226 ; gain 
of fertility through rotation, 228 ; 
necessity of excess plant-food, 
229 ; single crop system, 231 ; 
meadows, 234 ; fertilizing pays, 
236 ; green forage, 260 ; fertilizer 
constituents in, 16. 

Charcoal, animal, 67. 

Chemical analyses of fertilizers, the 
interpretation of, 175 ; agricul- 
tural value, 178; commercial 
value, 179; example, 180; how 
obtained, 181; schedule, 182; 
calculation of commercial value, 
187 ; uniformity of manufactured 
brands, 188; see Guarantee ; Pur- 
chase of fertilizers. 

Chemical composition of superphos- 
phate, 90. 

Chemical elements : in plants, 2, 
16 ; in soil, 3. 

Cherries, 325. 

Chicken manure, 125. 

Chives, 291. 

Citrous fruits, 325. 

Clay soil, imperfections of, 194. 

Clovers : characteristics, 201 ; fer- 
tilization, 225 ; green forage, 269 ; 
green manure, 130. 

Coal ashes, 112. 

Cocoa shells, 114. 

Collards, 293. 

Commercial valuation of fertilizers : 
relative value, 179 ; illustration, 
180; how calculated, 181 ; sched- 
ule of trade values, 182. 

Composts, 127. 

Corn-cob-ashes, 113. 

Corn : exhaustive of fertility ele- 
ments, 220; fertilizer constit- 
uents in, 16 ; for forage, 261. 

Corn, sweet, 305. 



Cost of farming, 29. 

Cotton, 333; formulas, 336; 

methods of application, 337. 
Cotton-seed rasal, 43. 
Cowpea and soybean, 271. 
Cranberries, 329. 
Crimson clover, see Clovers. 
Crude fish scrap, 104. 
Cucumbers, 299. 
Currants, 329. 

Deficiencies of the soil, 192. 
Derivation of a soil, 192. 
Direct manures, 22. 
Double manure salt, 98. 

Eggplant, 257, 297. 

Elements, essential of a fertilizer, 20. 

Extensive farming, 199. 

Farm labor, 28. 

Farm manures, see Manures. 

Farm practice, irrational, 17. 

Farm success, 1. 

Fertilizations, systems of, 204. 

Fertility : definition, 2 ; chemical 
elements needed, 2 ; influence of 
water, climate, season, 3 ; of 
physical character of soil, 4 ; of 
location of soil, 5 ; practical 
fertility, 6 ; potential fertility, 6 ; 
loss of fertility, 8 ; importance 
of careful culture, 9 ; loss of ni- 
trogen, 9 ; loss of mineral ele- 
ments, 11; artificial losses, 13; 
sale of crops, 13 ; improper 
handling of manures, 18. 

Fertility elements in crops, and 
prices received for same, 14. 

Fertilizers : essential elements, 20 ; 
natural and artificial, 21 ; direct, 
indirect, 22 ; available, unavail- 
able plant-food, 23 ; loss of 
soluble plant-food, 25 ; usefulness 
not dependent on source, 26 ; 
use of fertilizer, historical, 27 ; 
need of artificial fertilizer through 
changed conditions of farming, 
23-31 ; farm manures inadequate, 



Index 



361 



31 ; standard high grade mate- 
rials, 153. 

Complete, 165 ; purchase of, 
165. 

Home mixtures, 167 ; raw ma- 
terials, 168. 

Field beans, 258. 

Field truck crops : potatoes, 238 ; 
sweet potatoes, 244 ; tomatoes, 
248 ; peppers, 257 ; eggplant, 
257; peas, 257; beans, 257; 
field beans, 258. 

Fish, dried, 39 ; ground, 39 ; guano, 
39; scrap, 104. 

Flax, 351. 

Florida phosphate, 70. 

Flowering plants, 354. 

Fodder beets, 280. 

Forage crops, see Green forage. 

Forcing house crops, 354. 

Formulas of fertilizers, 169. 

Fruits, see Orchard fruits. 

Garbage tankage, 42. 

Garlic, 291. 

Gas lime, 116. 

Gooseberries, 329. 

Grapes, 339. 

Grasses, see Cereals ; character- 
istics, 200, 212; fertilization, 
226 ; green forage, 260 ; lawn, 
355. 

Green forage crops — 

Cereals and grasses, 260 ; maize 
corn, 261 ; wheat and rye, 263 ; 
spring rye, 264 ; oats, 265 ; oats 
and peas, 266 ; millet, 267 ; or- 
chard grass, 267 ; Italian rye 
grass, 268 ; Bermuda grass, 269. 
Clovers and legumes : Japan 
clover, 271 ; cowpea and soy- 
bean, 271 ; spring vetch, 271 ; 
alfalfa, 273 ; sweet clover, 274 ; 
need of lime, 274. 

Soiling crops, 275; scheme of 
practice of New Jersey Experi- 
ment Station, 276. 

Cabbage, 277 ; rape, 278 ; kohl- 
rabi, 279. 



Root crops, 279 : fodder beets, 
sugar beets, carrots, turnips and 
swedes, 280-281. 
Tuber crops, 282. 

Green-manures, see Manures. 

Green sand marl, 114. 

Ground burned lime, 139. 

Guano : bat, 46 ; fish, 39 ; natural, 
44 ; Peruvian, 45 ; Ichaboe, 46 ; 
phosphatic, 74. 

Guarantee of composition of fer- 
tilizer, 159 ; see Purchase of 
fertilizers. 

Gypsum, 116, 144. 

Hair waste, 43, 106. 

Hairy vetch, 272. 

Hard salt, 96. 

Herbs, 306. 

Herd grass, fertilizer constituents 

in, 16. 
High-grade mixtures, 169. 
Home mixtures, 167. 
Hops, 350. 

Horn, ground or meal, 42. 
Hydrated lime, 139. 

Ichaboe guano, 46. 
Intensive farming, 199. 
Iron phosphate, 72. 
Irrational farm practice, 17. 
Italian rye grass, 268. 

Japan clover, 271. 

Kaini, 95 ; on sweet potatoes, 244. 
Kale, 293. 
King crab, 109. 

Land phosphate, 69. 

Land plaster, 144. 

Land rock, 69. 

Lawn grasses, 355. 

Leather meal, 42. 

Leeks, 291. 

Legumes : nitrogen gatherers, 128 ; 
as green-manures, 128-134; green 
forage, 269 ; liming of legumes, 
274. 



362 



Index 



Lemons, 325. 

Lettuce, 296; fertilizer constitu- 
ents in, 16. 

Lime : lime and calcium com- 
pounds, 135-152 ; occurrence, 
136; forms on market, 136; 
action in soil, 140; mechanical 
effects, 141 ; chemical effects, 
142 ; upon organic matter, 143 ; 
upon potash, 143 ; upon phos- 
phates, 143 ; biological effects, 
145. 

Lime analyses, 152. 

Lime : forms on market, caustic, 
136 ; calcium magnesium, 138 
ground burned lime, 139 ; hy- 
drated, 139; air-slaked, 139 
oyster shell, 139 ; shell marl, 140 
Use of lime, 146 ; application 
148 ; form to use, 149 ; its cost 
150; legumes, 274; fruit trees 
310. 

Limestone, ground, 137. 

Linseed meal, 44. 

Lobster shells, 109. 

Low-grade mixtures, 169. 

Lucerne, alfalfa, 273. 

Maize, 261. 

"Make weight," 172. 

Manufactured brands, uniformity, 
188. 

Manures, natural vs. artificial, 21 ; 
direct and indirect effects, 20-22 ; 
inadequacy of farm manure, 32. 

Farm yard, 119-127; advan- 
tages, 119; variation, 120; 
sources of loss, 121 ; proper care, 
122 ; preservatives, 122 ; im- 
provement of, 123 ; application, 
124 ; poultry and chicken, 125 ; 
composts, 127. 

Green : 128-134 ; nitrogen 
gatherers and nitrogen con- 
sumers, 128; most useful crops, 
130 ; mixtures, 132 ; precau- 
tions, 133. 

Marble lime, 138. 

Market-garden crops : conditions 



of growth, 202, 283; basic 

fertilizer, 287 ; root crops, 289 ; 

bulb crops, 291 ; cole crops, 293 ; 

pot herbs, 294; salad, 295; 

pulse crops, 296 ; solanaceous 

crops, 297 ; vine crops, 299 ; 

miscellaneous, 300. 
Marl, green sand, 114; shell, 140. 
Meadows, 234. 
Meal: horn, 42; leather, 42; 

cottonseed, 43 ; linseed, 44. 
Menhaden, 105. 

Methods of use of fertilizers, 191. 
Millet, 267. 

Mineral phosphates, 68. 
Mixed fertilizers : agricultural 

value, 178 ; commercial value, 

179 ; calculation of values, 187 ; 

vs. raw materials, 165. 
Muck, 107. 
Muriate of potash, 96 ; on potatoes, 

242. 
Muskmelons, 299. 
Mussels, 109. 

Natural fertility, 1-19 ; see Fer- 
tility. 

Nitrate : of soda, 51 ; ammonium, 
53 ; calcium, 52 ; potassium, 53. 

Nitrate nitrogen, 50 ; see Nitrog- 
enous fertilizers. 

Nitrification, 50. 

Nitrogenous fertilizers, 36-59; defn. 
of "form of nitrogen," 36 
dried blood, 37 ; dried meat, etc. 
39 ; dried fish, 39 ; ground fish 
39 ; fish guano, 39 ; tankage, 40 
low-grade products, 42; vege- 
table nitrogenous products, 43 
cottonseed meal, 43 ; linseed 
meal, 44 ; castor pomace, 44 
vegetable pomaces, 44 ; natural 
guanos, 44 ; ammonia com- 
pounds, 47 ; sulfate of ammonia, 
48; calcium cyanamid, 49; ni- 
trate nitrogen, 50 ; nitrate of 
soda, 51 ; calcium nitrate, 52 ; 
potassium, 53 ; ammonium, 53 ; 
relative availability of different 



Index 



363 



forms, 53 ; conditions which 

modify, 57. 
Nitrogen gatherers, 128 ; nitrogen 

consumers, 128. 
Nitrogenous matter in phosphatic 

materials, 62 et seq. 

Oats : fertilizer constituents con- 
tained, 16; in rotation, 222 ; green 
forage, 265. 

Oats and peas, 266. 

Okra, 306. 

Onions, 29. 

Oranges, 325. 

Orchard fruits and berries : differ 
from general farm crops, 308; 
soil considerations, 311; fertiliz- 
ing in general, 312; apples, and 
pears, 314 ; peaches, experiments 
and results, 318 ; plums, cherries, 
apricots, 325 ; citrous fruits, 
325 ; small fruits, 326 ; cran- 
berries, 329. 

Orchard grass, 267. 

Organic nitrogen : defn., 23, 1 37 ; 
various forms in use, 37-47 ; 
availability, 47. 

Oxy-acetylene residue, 118. 

Oyster-shell lime, 139. 

Palmaer phosphate, 74. 

Parsnips, fertilizer constituents in, 
16. 

Peaches, 318; experiments at New 
Jersey Experiment station, 318. 

Peanuts, 354. 

Pears, 314. 

Peas : field truck, 258 ; green forage, 
266 ; cowpea, 271 ; market gar- 
den, 296. 

Peat, 107. 

Pebble phosphate, 70. 

Peppers, 257, 298. 

Peruvian guano, 45. 

Phosphate of lime, 62, 81. 

Phosphates : organic substances, 
62 et seq.; mineral phosphates, 
68 et seq. ; manufactured phos- 
phates, 73 ; sources of phos- 



phoric acid to plants, 75 ; in- 
fluence of source, 76 ; of fine- 
ness, 77 ; of character of soil, 77 ; 
of kind of crop, 78 ; general use- 
fulness, 78 ; comparison with 
superphosphates, 85. 

Phosphatic materials : phosphate of 
lime, 62 ; bone phosphate, 62 ; 
animal phosphate, 62 ; raw bone, 
63 ; boiled steamed bone, 64 ; 
commercial grades of bone, 65 ; 
bone tankage, 66; bone black, 
66 ; animal charcoal, 67 ; bone 
ash, 68 ; Florida rock, 70 ; Cana- 
dian apatite, 71 ; Tennessee, 
71 ; superphosphates, 81 et seq. 

Phosphoric acid : derivation, 61 ; 
in animal matter, 62 ; guarantees 
and grades, 65 ; in mineral 
matter, 68 ; in basic slag, 72 ; in 
manufactured phosphates, 73 ; 
derived by plant from phosphates 
through decay, 76; conditions 
which affect availability, 76 ; 
forms : insoluble, 81 ; soluble, 
82, 84; reverted, 82; "free" 
phosphoric acid, 91 ; soluble in 
water, but fixed in soil, 92. 

Phosphorus powder, 117. 

Pigeon manure, 46, 125. 

Plant-food, available, unavailable, 
23. 

Plaster, land, 144. 

Plums, 328. 

Potash : importance, 93 ; avail- 
ability, 94. 

Forms : crude products, 95- 
100 ; manufactured products, 96 ; 
fixation in soil, 100. 

Sources of : kainit, 95 ; hard- 
salt, 96 ; carnallit, 96 ; muriate, 
96 ; high-grade sulfate, 97 ; 
double manure salt, 98 ; potash 
manure salt, 98 ; double car- 
bonate of potash and magnesia, 
98 ; carbonate, 99 ; nitrate, 99 ; 
feldspar, 99 ; seaweeds, 100. 

Potatoes : fertilizer constituents in, 
16 ; in crop rotation, 209 ; field 



364 



Index 



truck crop, 238-244 ; early, 238 ; 
formulas, late, 243, formulas, 
roughage, 282. 

Potential fertility, 6. 

Poultry manure, 46, 125. 

Powder waste, 116. 

Power of plant to acquire food, 199. 

Practical fertility, 6. 

Previous treatment of soil, 195. 

Prices received for fertility ele- 
ments in crops removed, 14. 

Pulse, crops, 296. 

Pumpkins, 299. 

Purchase of fertilizers : standard 
high-grade materials, 154 ; va- 
riable materials, 155 ; unit basis 
of fertilizers, 157 ; ton basis of 
fertilizers, 157 ; guarantee a 
necessity, 158 ; relation of guar- 
antee to selling price, 159 ; dis- 
cussion, 162; raw materials vs. 
mixed fertilizers, 165 ; home 
mixtures, 167 ; formulas, 169 ; 
general advice, 173. 

Rape, 278. 

Raspberries, 326. 

Raw bone, 63. 

Raw material vs. mixed fertilizers, 

165. 
Rhubarb, 304. 
River phosphate, 69. 
River rock phosphate, 69. 
Rock phosphates, 69. 
Root crops : characteristics, 202 ; 

for green forage, 279 ; for market 

garden, 289. 
Roses, 354. 
Rotation of crops, 209 ; gain in 

fertility in soil, 228. 
Rye, 225 ; fertilizer constituents in, 

16 ; forage crop, 263 ; spring rye, 

264. 
Rye grass, Italian, 269. 

Salt, 115, 

Sandy soils : imperfections, 194. 
Seaweeds, source of potash, 100, 110. 
Sewage, 107. 



Shallots, 291. 

Shell marl, 140. 

Slag, basic, 72 ; meal, 73. 

Soda, nitrate of, see Nitrate. 

Soft phosphate, 70. 

Soil fertility, see Fertility. 

Soiling crops, 275. 

Soils: derivation, guide to possible 
imperfections, 192 ; clay, 194 ; 
sandy, 194 ; influence of previous 
treatment, 195. 

Solanaceous crops, 297. 

Soluble plant-food, danger of loss, 
25. 

Sorghum, 352. 

South Carolina rock phosphates, 69. 

Soybean and cowpea, 271. 

Spinach, 294. 

Spring vetch, 272. 

Squash, 299. 

Standard high-grade materials, 153. 

Strawberries, 326. 

Sugar beets, 280, 343-347. 

Sugar cane, 347 ; Louisiana experi- 
ments, 347. 

Sulfate of ammonia, 48. 

Sulfate of lime see Gypsum. 

Sulfate of potash, 97 ; on potatoes, 
242. 

Superphosphates, 61, 82; process 
of manufacture, 83 ; differences 
in superphosphates, 84 ; phos- 
phates vs. superphosphates, 85; 
reversion, 87 ; double superphos- 
phates, 89: "total available," 
89 ; chemical composition, 90. 

Swedes, 281. 

Sweet corn, 305. 

Sweet potatoes, 244-248; rough- 
age, 282. 

Systems of fertilizing : 1 . based 
upon the influence of a single 
element, 204; 2. based upon 
need of abundant supply of min- 
erals, 205 ; see also "Use" of fer- 
tilizers. 

Tanbark ashes, 111. 

Tankage, 40 ; garbage, 42 ; bone, 66. 



Index 



365 



Tennessee phosphate, 71. 

Tetracalcic phosphoric acid, 83. 

Thomas phosphate powder, 72. 

Timothy, 226 ; fertilizer constit- 
uents in, 16. 

Tobacco, 338 ; influence of fer- 
tilizer upon quality, 339 ; Con- 
necticut experiments, 339 ; mu- 
riate of potash, 95. 

Tobacco stems, 103 ; salts, 104. 

Tomatoes : field truck, 248 ; mar- 
ket garden, 298. 

Ton basis of purchase of fertilizer, 
157. 

Trade values of fertilizers, 179 ; 
how obtained, 181 ; schedule of, 
182. 

Tricalcic phosphoric acid, 82. 

Truck crops, see Field truck crops, 
237. 

Tuber crops, 282, 289. 

Turnips : for forage, 281 ; for 
market garden, 289. 

Uniformity of manufactured 
brands, 189. 

Unit basis of purchase of fertilizers, 
157. 

Use of fertilizers : conditions which 
modify usefulness of fertilizers, 
191 : derivation of soil, 192 ; 
physical imperfections of soil, 
194 ; previous treatment of soil, 
195; character of crop, 197; 
kind of farming, 199. 

Variations of plants, 199 ; cere- 
als, 200 ; grasses and clovers, 200 ; 
root crops, 202 ; market garden, 
202 ; fruit crops, 203. 

Systems suggested based on : 



1. influence of single element, 
204; 2. abundant supply of 
minerals, 205 ; 3. needs of plant 
as determined by chemical analy- 
sis, 207 ; 4. stimulation of the 
"money crop" in the rotation, 
209. 

Irrational system, 210. 

Value of a fertilizer, 178, 189. 

Variable materials, 155. 

Vegetable matter in fertilizers, 
effect upon physical character of 
the soil, 21. 

Vegetable nitrogenous products, 
43 ; pomaces, 44. 

Vegetables (see Market garden 
crops), 202, 283; fertilizer con- 
stituents in, 16. 

Vetch : spring, 272 ; hairy or 
winter, 272. 

Ville George : his system of fer- 
tilizing, 204. 

Wages, in regard to fertilizers, 29, 
205. 

Wagner system, 205. 

Waste: calcium carbide, 117; wool 
and hair, 43, 106; powder, 116. 

Water, its influence upon soil fer- 
tility, 3. 

Watermelons, 299. 

Wheat : fertility content of, 14 ; 
fertilization, 224; for green 
forage, 263. 

Wiborgh phosphate, 74. 

Winter vetch, 272. 

Wolter phosphate, 74. 

Wood ashes, 111. 

Wool waste, 43, 106. 



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ADDITIONS TO THE RURAL SCIENCE SERIES 
Edited by L. H. Bailey 



The Strawberry in North America 
By S. W. FLETCHER 

Illustrated, cloth, i2mo 

This work is not only a practical guide to strawberry grow- 
ing but also a sketch of the evolution of the strawberry in 
North America, from the wilding of colonial days to its pres- 
ent position as the most cosmopolitan of American fruits, 
second only to the apple in commercial importance. The 
volume includes chapters on the early history of the straw- 
berry in the old world and the new, the botany and origin of 
the cultivated strawberry, the rise of strawberry culture and 
the different ways in which it is practiced in different parts 
of the country, with something of an attempt to elucidate the 
principles that underlie these practices. 

Subtropical Vegetable-Gardening 
By P. H. ROLFS 

Illustrated, cloth, i2tno 

This work is a distinct contribution to the literature of 
vegetable gardening. Professor Rolfs confines himself to 
subtropical experience, but his book will prove invaluable to 
growers in a wide territory of the United States. Definite 
information is given regarding production of various crops 
and all new or unusual vegetables are discussed. 



THE MACMILLAN COMPANY 

Publishers 64-66 Fifth Avenue New York 



LIBRARY OF CONGRESS 



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